Stabilized magnetic force devices, systems and methods

ABSTRACT

Devices, systems, and methods employ at least one ferromagnetic structure sized and configured for placement in a tissue region. A component is attached to the structure to stabilise its placement in the tissue region. An anchoring structure holds the component in a state of tension. The anchoring structure can, e.g., take the from of an anchoring body that expands in situ. The anchoring structure can be adjustable for adjusting the state of tension. The component can be elastic, to deflect under load in a prescribed manner and to recover an initial shape when unloaded.

RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. patentapplication Ser. No. 11/592,529, filed Nov. 3, 2006, which is acontinuation-in-part of U.S. application Ser. No. 10/718,254, filed Nov.20, 2003 (now U.S. Pat. No. 7,360,542), which is a continuation-in-partof U.S. patent application Ser. No. 10/656,861, filed Sep. 6, 2003 (nowU.S. Pat. No. 7,188,627), which further claims the benefit of U.S.Provisional Patent Application Ser. No. 60/456,164, filed Mar. 20, 2003,and U.S. Provisional Patent Application Ser. No. 61/441,639, filed Jan.22, 2003, which is a continuation-in-part of U.S. patent applicationSer. No. 10/236,455, filed Sep. 6, 2002 (now U.S. Pat. No. 7,216,648).

FIELD OF THE INVENTION

The invention is directed to devices, systems, and methods for thetreatment of sleep disordered breathing including obstructive sleepapnea and snoring.

BACKGROUND OF THE INVENTION I. Characteristics of Sleep Apnea

First described in 1965, sleep apnea is a breathing disordercharacterized by brief interruptions (10 seconds or more) of breathingduring sleep. Sleep apnea is a common but serious, potentiallylife-threatening condition, affecting as many as 18 million Americans.

There are two types of sleep apnea: central and obstructive. Centralsleep apnea, which is relatively rare, occurs when the brain fails tosend the appropriate signal to the breathing muscles to initiaterespirations, e.g., as a result of brain stem injury or damage.Mechanical ventilation is the only treatment available to ensurecontinued breathing.

Obstructive sleep apnea (OSA) is far more common. Normally, the musclesof the upper part of the throat keep the airway open to permit air flowinto the lungs. When the muscles of the soft palate, the base of thetongue, and the uvula (the small fleshy tissue hanging from the centerof the back of the throat) relax and sag, the relaxed tissues mayvibrate as air flows past the tissues during breathing, resulting insnoring. Snoring affects about half of men and 25 percent of women—mostof whom are age 50 or older.

In more serious cases, the airway becomes blocked, making breathinglabored, or even stopping it altogether. In a given night, the number ofinvoluntary breathing pauses or “apneic events” may be as high as 20 to30 or more per hour. These breathing pauses are almost alwaysaccompanied by snoring between apnea episodes, although not everyone whosnores has the condition. Sleep apnea can also be characterized bychoking sensations.

Lack of air intake into the lungs results in lower levels of oxygen andincreased levels of carbon dioxide in the blood. Upon an apneic event,the sleeping person is unable to continue normal respiratory functionand the level of oxygen saturation in the blood is reduced. The brainwill sense the condition and cause the sleeper to struggle and gasp forair. Breathing will then resume, often followed by continued apneicevents. There are potentially damaging effects to the heart and bloodvessels due to abrupt compensatory swings in blood pressure. Upon eachevent, the sleeping person will be partially aroused from sleep,resulting in a greatly reduced quality of sleep and associated daytimefatigue. The frequent interruptions of deep, restorative sleep oftenlead to early morning headaches, excessive daytime sleepiness,depression, irritability, and learning and memory difficulties.

The medical community has become aware of the increased incidence ofheart attacks, hypertension and strokes in people with moderate orsevere obstructive sleep apnea. It is estimated that up to 50 percent ofsleep apnea patients have high blood pressure.

Although some apneic events are normal in all persons and mammals, thefrequency of blockages will determine the seriousness of the disease andpotential for health damage. When the incidence of blockage is frequent,corrective action should be taken.

II. The Anatomy of the Upper Airway

As FIG. 1 shows, the upper airway consists of a conduit that begins atthe nasal valve, situated in the tip of the nose, and extends to thelarynx, which is also called the voice box because it houses the vocalcords. The pharynx (which, in Greek, means “throat”) is a cone-shapedpassageway in the upper airway that leads from the oral and nasalcavities in the head to the esophagus and larynx. The pharynx servesboth respiratory and digestive functions. Both circular and longitudinalmuscles are present in the walls of this organ, which are called thepharyngeal walls. The circular muscles form constrictions that help pushfood to the esophagus and prevent air from being swallowed, while thelongitudinal muscles lift the walls of the pharynx during swallowing.

The pharynx consists of three main divisions. The anterior portion isthe nasal pharynx, the back section of the nasal cavity. The nasalpharynx connects to the second region, the oral pharynx, by means of apassage called an isthmus. The oral pharynx begins at the back of themouth cavity and continues down the throat to the epiglottis, a flap oftissue that covers the air passage to the lungs and that channels foodto the esophagus. The isthmus connecting the oral and nasal regionsallows humans to breathe through either the nose or the mouth. The thirdregion is the laryngeal pharynx, which begins at the epiglottis andleads down to the esophagus. Its function is to regulate the passage ofair to the lungs and food to the esophagus. Air from the nasal cavityflows into the larynx, and food from the oral cavity is routed to theesophagus directly behind the larynx. The epiglottis, a cartilaginous,leaf-shaped flap, functions as a lid to the larynx and, during the actof swallowing, controls the traffic of air and food.

The mouth cavity marks the start of the digestive tube. Oval in shape,it consists of two parts: the vestibule and the mouth cavity proper.

The vestibule is the smaller outer portion, delimited externally by thelips and cheeks and internally by the gums and teeth. It connects withthe body surface through the rima or orifice of the mouth. The vestibulereceives the secretion of the parotid salivary glands and connects whenthe jaws are closed with the mouth cavity proper by an aperture on bothsides behind the wisdom teeth, and by narrow clefts between opposingteeth.

The mouth cavity proper contains the tongue and is delimited laterallyand in the front by the alveolar arches with the teeth thereincontained. It receives the secretion from the submaxillary andsublingual salivary glands. The mouth cavity proper connects with thepharynx by a constricted aperture called isthmus faucium.

The tongue is a mobile muscular organ that can assume a variety ofshapes and positions. The tongue has a relatively fixed inferior partthat is attached to the hyoid bone and mandible. The rest of the tongueis called the body of the tongue. It is essentially a mass of musclesthat is mostly covered by mucous membrane. The muscles in the tongue donot act in isolation. Some muscles perform multiple actions with partsof one muscle acting independently producing different, sometimesantagonistic, actions.

The tongue is partly in the mouth or oral cavity and partly in thepharynx. At rest, it occupies essentially all of the oral cavity. Theposterior part of the tongue demarcates the posterior boundary of theoral cavity. Its mucous membrane is thick and freely movable.

The tongue is involved with mastication, taste, articulation, and oralcleansing. Its two main functions are forming words during speaking andsqueezing food into the pharynx when swallowing.

The palate forms the arched roof of the oral or mouth cavity (the mouth)and the floor of the nasal cavities (the nose). It separates the oralcavity from the nasal cavities and the nasal pharynx. The palateconsists of two regions—the hard palate anteriorly and the soft palateposteriorly.

The hard palate is vaulted and defines the space filled by the tonguewhen it is at rest. The hard palate has a hard bony skeleton, hence itsname.

The soft palate has no bony skeleton, hence its name. The soft palate issuspended from the posterior border of the hard palate. It extendsposteriorly and inferiorly as a curved free margin from which hangs aconical process, called the uvula. Muscles arise from the base of thecranium and descend into the soft palate. The muscles allow the softpalate to be elevated during swallowing into contact with the posteriorpharyngeal wall. The muscles also allow the soft palate to be drawninferiorly during swallowing into contact with the posterior part of thetongue.

The soft palate is thereby very dynamic and movable. When a personswallows, the soft palate initially is tensed to allow the tongue topress against it, to squeeze the bolus of food to the back of the mouth.The soft palate is then elevated posteriorly and superiorly against thepharyngeal wall, acting as a valve which closes and prevents passage offood into the nasal cavity.

III. Sleep and the Anatomy of the Upper Airway

Although all tissue along this conduit is dynamic and responsive to therespiratory cycle, only the pharynx, in particular the nasopharynx (thearea at the soft palate and the pharyngeal walls) and the oropharynx(the area at the tongue base and the pharyngeal walls), is totallycollapsible. The pharyngeal structures and individual anatomiccomponents within this region include the pharyngeal walls, the base ofthe tongue, the soft palate with uvula, and the epiglottis.

The cross sectional area of the upper airway varies with the phases ofthe respiratory cycle. At the initiation of inspiration (Phase I), theairway begins to dilate and then to remain relatively constant throughthe remainder of inspiration (Phase II). At the onset of expiration(Phase III) the airway begins to dilate, reaching maximum diameter andthen diminishing in size so that at the end of expiration (Phase IV), itis at its narrowest, corresponding to the time when the upper airwaydilator muscles are least active, and positive intraluminal pressure islowest. The upper airway, therefore, has the greatest potential forcollapse and closure at end-expiration [ref: Schwab R J, Goldberg A N.Upper airway assessment: radiographic and other imaging techniques.Otolaryngol Clin North Am 1998: 31:931-968].

Sleep is characterized by a reduction in upper airway dilator muscleactivity. For the individual with obstructive sleep apnea (OSA) andperhaps the other disorders which comprise much of the group of entitiescalled obstructive sleep-disordered breathing (SDB), it is believed thatthis change in muscle function causes pharyngeal narrowing and collapse.Two possible etiologies for this phenomenon in OSA patients have beentheorized. One is that these individuals reduce the airway dilatormuscle tone more than non-apneics during sleep (the neural theory). Theother is that all individuals experience the same reduction in dilatoractivity in sleep, but that the apneic has a pharynx that isstructurally less stable (the anatomic theory). Both theories may infact be contributors to OSA, but current studies seem to support thatOSA patients have an intrinsically structurally narrowed and morecollapsible pharynx [ref: Isono S. Remmers J, Tanaka A Sho Y, Sato J,Nishino T. Anatomy of pharynx in patients with obstructive sleep apneaand in normal subjects. J Appl Physiol 1997:82:1319-1326.] Although thisphenomenon is often accentuated at specific sites, such as thevelopharyngeal level [Isono], studies of closing pressures [Isono]supports dynamic fast MRI imaging that shows narrowing and collapseusually occurs along the entire length of the pharynx [ref: Shellock FG, Schatz C J, Julien P, Silverman J M, Steinberg F, Foo T K F, Hopp ML, Westbrook P R. Occlusion and narrowing of the pharyngeal airway inobstructive sleep apnea: evaluation by ultrafast spoiled GRASS MRimaging. Am J of Roentgenology 1992:158:1019-1024].

IV. Treatment Options

To date, the only modality that addresses collapse along the entireupper airway is mechanical positive pressure breathing devices, such ascontinuous positive airway pressure (CPAP) machines. All othermodalities, such as various surgical procedures and oral appliances, bytheir nature, address specific sectors of the airway (such as palate,tongue base and hyoid levels), but leave portions of pharyngeal walluntreated. This may account for the considerably higher success rate ofCPAP over surgery and appliances in controlling OSA. Although CPAP,which in essence acts as an airway splint for the respiratory cycle, ishighly successful, it has some very significant shortcomings. It can becumbersome to wear and travel with, difficult to accept on a sociallevel, and not tolerated by many (for reasons such as claustrophobia,facial and nasal mask pressure sores, airway irritation). These factorshave lead to a relatively poor long-term compliance rate. One study hasshown that 65% of patients abandon their CPAP treatment in 6 months.

Other current treatments for OSA include genioglossal advancement (GA)and maxillomandibular advancement (MMA). These treatments involve highlyinvasive surgical procedures and a long recovery time, and thereforehave relatively low patient appeal.

The need remains for simple, cost-effective devices, systems, andmethods for reducing or preventing sleep disordered breathing events.

SUMMARY OF THE INVENTION

The present invention provides devices, systems, and methods that employat least one ferromagnetic structure sized and configured for placementin a tissue region. An attachment component is attached to thestructure, which is held in tension to stabilize placement of thestructure in the tissue region.

One aspect of the invention provides at least one anchoring structurethat is sized and configured for placement in a tissue region spacedfrom the at least one ferromagnetic structure. According to this aspectof the invention, the anchoring structure includes an expandablestructure capable of movement between a collapsed condition and anexpanded condition within tissue. The attachment component couples theanchoring structure to the ferromagnetic structure to stabilize theferromagnetic structure in the tissue region.

Another aspect of the invention provides at least one anchoringstructure that is sized and configured for placement in a tissue regionspaced from the at least one ferromagnetic structure. In thisarrangement, the attachment component includes an attachment assemblythat couples the anchoring structure to the ferromagnetic structure. Theattachment assembly includes a first end coupled to the ferromagneticstructure and a second end coupled to the anchoring structure to holdthe attachment component in a state of tension. According to this aspectof the invention, the second end includes a member for adjusting thestate of tension.

Another aspect of the invention provides at least one elastic componentcoupled to the ferromagnetic material. The elastic component is sizedand configured to deflect under load in a prescribed manner and torecover an initial shape when unloaded. In one embodiment, the elasticcomponent comprises a spring-form.

Another aspect of the invention provides a system that includes thestabilized ferromagnetic structure as above described in associationwith at least one additional ferromagnetic structure sized andconfigured for placement in a desired relationship with theferromagnetic structure to magnetically interact with the stabilizedferromagnetic structure.

Another aspect of the invention provides a method for stabilizing adesired tissue orientation by magnetic interaction between thestabilized ferromagnetic structure and the additional ferromagneticstructure. The method can be used, e.g., for reducing or preventingsleep disordered breathing events.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an anatomic side section view of the upper airway of a human,showing the nasal and oral cavities, tongue, hard palate, soft palate,oral pharynx, chin and neck.

FIG. 2 is an anatomical anterior view of the oral cavity, where thetongue has been pulled towards the front to show the roof of the mouthcomprising the hard palate (in the front) and the soft palate (in theback).

FIG. 3 is an anatomical side view, with sections partly broken away andin section, of a human suffering from one form of sleep apnea involvingthe soft palate, showing how the tongue base, the soft palate, and theuvula lean against the pharyngeal wall, effectively closing off theairway, resulting in an apneic event.

FIGS. 4A to 4D show in a diagrammatic way representative embodiments ofa magnetic force system that resists occurrence of the tissue conditionshown in FIG. 3, involving the collapse of a tongue against thepharyngeal wall, with FIGS. 4A and 4C showing magnetic interaction of aferromagnetic structure implanted in regions of a tongue with a magneticstructure carried outside an airway (e.g., on a chin and/or jaw), andwith FIGS. 4B and 4D showing magnetic interaction of a ferromagneticstructure implanted in regions of a tongue with a magnetic structurecarried inside an airway (e.g., in an oral cavity). FIGS. 4E and 4F showalternative embodiments of the Tongue System that provide an additionalrepelling force to resist the collapse of the tongue.

FIGS. 5A and 5B show in a diagrammatic way representative embodiments ofa magnetic force system that resists occurrence of the tissue conditionshown in FIG. 3, involving the collapse of a soft palate/uvula againstthe pharyngeal wall, with FIG. 5A showing magnetic interaction of aferromagnetic structure implanted in a soft palate/uvula with a magneticstructure carried outside an airway (e.g., on a chin and/or jaw), andwith FIG. 5B showing magnetic interaction of a ferromagnetic structureimplanted in a soft palate/uvula with a magnetic structure carriedinside an airway (e.g., in an oral cavity). FIGS. 5C and 5D showalternative embodiments of the Soft Palate System that provide anadditional repelling force to resist the collapse of the softpalate/uvula.

FIGS. 6A and 6B show in a diagrammatic way representative embodiments ofa magnetic force system that resists occurrence of the tissue conditionshown in FIG. 3, involving the collapse of both a tongue and a softpalate/uvula against the pharyngeal wall, with FIG. 6A showing magneticinteraction of ferromagnetic structures implanted in a tongue and a softpalate/uvula with a magnetic structure carried outside an airway (e.g.,on a chin and/or jaw), and with FIG. 6B showing magnetic interaction offerromagnetic structures implanted in a tongue and a soft palate/uvulawith a magnetic structure carried inside an airway (e.g., in an oralcavity). FIGS. 6C and 6D show alternative embodiments of the CombinedSystem that provide an additional repelling force to resist the collapseof the tongue and soft palate/uvula.

FIGS. 7A to 7C show representative embodiments of magnetic structuressized and configured to be worn on a jaw and/or a chin outside an airwayto magnetically interact with one or more magnetic structures carriedwithin an airway, e.g., in or on a tongue and/or soft palate/uvula inthe manner shown in FIGS. 4A, 4C, 5A, and 6A.

FIGS. 8A and 8B show representative embodiments of magnetic structuressized and configured to be worn about a neck outside an airway tomagnetically interact with one or more ferromagnetic structures carriedwithin an airway, e.g., in or on a tongue and/or soft palate/uvula inthe manner shown in FIGS. 4A, 4C, 5A, and 6A.

FIGS. 9A to 9E show representative embodiments of a magnetic structuressized and configured to be worn within an airway, e.g., on teeth withinan oral cavity, to magnetically interact with ferromagnetic structurescarried within an airway, e.g., in or on a tongue and/or softpalate/uvula in the manner shown in FIGS. 4B, 4D, 5B, and 6B.

FIG. 10 is a perspective view of a ferromagnetic material sized andconfigured for implantation as part of a magnetic force system shown inFIGS. 4A to 4D, or 5A or 5B, or 6A or 6B.

FIG. 11 is a perspective view of an array of ferromagnetic materials ina carrier that is sized and configured for implantation as part of themagnetic force system shown in FIGS. 4A to 4D, or 5A or 5B, or 6A or 6B.

FIG. 12A is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4A or 4Ccomprising a ferromagnetic structure implanted in a region of a tonguethat interacts with a magnetic structure carried outside an airway(e.g., on a chin and/or jaw), to resist occurrence of the tissuecondition shown in FIG. 3, involving the collapse of a tongue againstthe pharyngeal wall.

FIG. 12B is a perspective view of a ferromagnetic structure sized andconfigured to be implanted in a region of a tongue and forming a part ofthe system shown in FIG. 12A.

FIGS. 12C and 12D are, respectively, a perspective view and a side viewof a magnetic structure sized and configured to be worn outside anairway (e.g., on a chin and/or jaw) and forming a part of the systemshown in FIG. 12A.

FIG. 12E is an anatomical anterior view of the oral cavity, showing thetongue and the hard and soft palates, and further showing the magneticforce system as shown in FIG. 12A, in which the ferromagnetic structurein the tongue extends generally symmetrically across the centerline ofthe tongue and the magnetic structure worn on the chin and/or jawincludes magnets on both lateral sides of the oral cavity, and furthershowing in this arrangement the magnetic attracting forces that resistoccurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIG. 12F is an anatomical anterior view of the oral cavity, showing thetongue and the hard and soft palates, and further showing the magneticforce system as shown in FIG. 12A, in which the ferromagnetic structurein the tongue extends generally symmetrically across the centerline ofthe tongue and the magnetic structure worn on the chin and/or jawincludes magnets only on one lateral side of the oral cavity, andfurther showing in this arrangement the magnetic attracting forces thatresist occurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIG. 12G is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4B or 4Dcomprising a ferromagnetic structure implanted in a region of a tonguethat interacts with a magnetic structure carried inside an airway (e.g.,within an oral cavity), to resist occurrence of the tissue conditionshown in FIG. 3, involving the collapse of a tongue against thepharyngeal wall.

FIG. 12H is an anatomical anterior view of the oral cavity, showing thetongue and the hard and soft palates, and further showing the magneticforce system as shown in FIG. 12G, in which the ferromagnetic structurein the tongue extends generally symmetrically across the centerline ofthe tongue and the magnetic structure worn within the oral cavityincludes magnets on both lateral sides of the oral cavity, and furthershowing in this arrangement the magnetic attracting forces that resistoccurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIG. 13A is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4B or 4Dcomprising a ferromagnetic structure implanted in a region of a tonguethat interacts with a magnetic structure carried inside an airway (e.g.,in an oral cavity), to resist occurrence of the tissue condition shownin FIG. 3, involving the collapse of a tongue against the pharyngealwall.

FIG. 13B is a perspective view of a ferromagnetic structure sized andconfigured to be implanted in a region of a tongue and forming a part ofthe system shown in FIG. 13A.

FIG. 13C is a perspective view of a magnetic structure sized andconfigured to be worn within an airway, e.g., on teeth within an oralcavity, and forming a part of the system shown in FIG. 13A.

FIG. 13D is an anatomical anterior view of the oral cavity, showing thetongue and the hard and soft palates, and further showing the magneticforce system as shown in FIG. 13A, in which the ferromagnetic structurein the tongue extends generally symmetrically across the centerline ofthe tongue and the magnetic structure worn on teeth within an oralcavity includes magnets on both lateral sides of the oral cavity, andfurther showing in this arrangement the magnetic attracting forces thatresist occurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIG. 14A is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 6Bcomprising ferromagnetic structures implanted in a region of a tongueand soft palate/uvula that interact with a magnetic structure carriedinside an airway (e.g., in an oral cavity), to resist occurrence of thetissue condition shown in FIG. 3, involving the collapse of a tongue andsoft palate/uvula against the pharyngeal wall.

FIG. 14B is a perspective view of a ferromagnetic structure sized andconfigured to be implanted in a region of a tongue and a softpalate/uvula, and forming a part of the system shown in FIG. 14A.

FIG. 14C is a perspective view of a magnetic structure sized andconfigured to be worn within an airway, e.g., on teeth within an oralcavity, and forming a part of the system shown in FIG. 14A.

FIG. 14D is an anatomical anterior view of the oral cavity, showing thetongue and the hard and soft palates, and further showing the magneticforce system as shown in FIG. 14A, in which the ferromagnetic structuresin the tongue and soft palate/uvula extend generally symmetricallyacross the centerline of the tongue and soft palate and the magneticstructure worn on teeth within an oral cavity includes magnets on bothlateral sides of the oral cavity, and further showing in thisarrangement the magnetic attracting forces that resist occurrence of thetissue condition shown in FIG. 3, involving the collapse of a tongueagainst the pharyngeal wall.

FIG. 15 is a graph showing how magnetic force is sensitive to distance(curve SM) and how titration of a magnetic force field (curve MM) canreduce with sensitivity of the force-distance relationship with aprescribed working space defined during normal anatomic functions of atongue and soft palate/uvula.

FIGS. 16A and 17A are diagrammatic views of a titrated magneticstructure carried on a chin or jaw outside an airway or on teeth in anairway that interacts with a ferromagnetic structure implanted in atongue or a soft palate/uvula, also showing in this arrangement how themagnetic attracting forces have been moderated by the titration to thesensitivity of the force-distance relationship with a prescribed workingspace defined during normal anatomic functions of a tongue and softpalate/uvula.

FIGS. 16B and 17B are diagrammatic views of a titrated magneticstructure worn about a neck outside an airway that interacts with aferromagnetic structure implanted in a tongue or a soft palate/uvula,also showing in this arrangement how the magnetic attracting forces thathave been moderated by the titration to the sensitivity of theforce-distance relationship with a prescribed working space definedduring normal anatomic functions of a tongue and soft palate/uvula.

FIGS. 18A and 18B are diagrammatic representations of a finite elementanalysis showing the flux lines for the titrated magnetic structures ofthe type shown in FIGS. 16A/16B and 17A/17B, demonstrating how themagnetic attracting forces have been moderated by titration to thesensitivity of the force-distance relationship with a prescribed workingspace defined during normal anatomic functions of a tongue and softpalate/uvula.

FIG. 19 is an anatomic side section view of the upper airway of a human,showing the nasal and oral cavities, tongue, hard palate, soft palate,oral pharynx, chin and neck, and further showing a representativemagnetic force system of a type shown in FIG. 4A in which aferromagnetic structure implanted in a region of a tongue includesmobile ferromagnetic material that interacts with a magnetic structurecarried outside an airway (e.g., on a chin and/or jaw), to resistoccurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue and soft palate/uvula against the pharyngeal wall.

FIGS. 20A and 20B are anatomic side section views of the upper airway ofa human, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4B in whicha ferromagnetic structure implanted in a region of a tongue includesmobile ferromagnetic material that interacts with a magnetic structurecarried inside an airway (e.g., on teeth within an oral cavity), toresist occurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue and soft palate/uvula against the pharyngeal wall.

FIG. 21A is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4A in whicha ferromagnetic structure implanted in a region of a tongue interactswith a magnetic structure that includes mobile magnetic material carriedoutside an airway (e.g., on a chin and/or jaw), to resist occurrence ofthe tissue condition shown in FIG. 3, involving the collapse of a tongueand soft palate/uvula against the pharyngeal wall.

FIGS. 21B to 21F are perspective views of representative embodiments ofa magnetic structure sized and configured to be worn within an airway,e.g., on teeth within an oral cavity, that includes mobile magneticmaterial, forming a part of the system shown in FIG. 21A.

FIG. 22A is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 5B, inwhich a ferromagnetic structure implanted in a region of a softpalate/uvula interacts with a magnetic structure that includes mobilemagnetic material carried inside an airway (e.g., on teeth within anoral cavity), to resist the occurrence of the tissue condition shown inFIG. 3, involving the collapse of a tongue and soft palate/uvula againstthe pharyngeal wall.

FIGS. 22B and 22C are perspective views of representative embodiments ofa magnetic structure sized and configured to be worn within an airway,e.g., on teeth within an oral cavity, that includes mobile magneticmaterial, forming a part of the system shown in FIG. 22A.

FIG. 23A is an anatomic side section view of the upper airway of ahuman, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4A in whicha ferromagnetic structure implanted in a region of a tongue includesmobile ferromagnetic material that interacts with a magnetic structurecarried outside an airway (e.g., on a chin and/or jaw), to resistoccurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue and soft palate/uvula against the pharyngeal wall.

FIGS. 23B and 23C are perspective views of representative embodiments ofa magnetic structure sized and configured to be implanted in a region ofa tongue that includes mobile magnetic material, forming a part of thesystem shown in FIG. 23A.

FIGS. 24A, 24B, and 24C are representative diagrammatic embodiments ofmobile ferromagnetic materials of various shapes and forms that can forma part of the systems shown in FIG. 19; FIGS. 20A and 20B; FIGS. 21A to21F; FIGS. 22A to 22C; or FIGS. 23A to 23C.

FIG. 25 is an anatomical superior view of the oral cavity, showing thetongue and pharyngeal conduit, and further showing a ferromagneticstructure implanted in a tongue, in which the ferromagnetic structureextends generally asymmetrically only on one lateral side of the tongue,the view also showing a tissue condition as shown in FIG. 3, involvingthe collapse of a tongue against the pharyngeal wall.

FIG. 26A is an anatomical superior view of the oral cavity, like thatshown in FIG. 25, in which the ferromagnetic structure implantedasymmetrically in the tongue interacts with a magnetic structure insidean airway (e.g., on teeth within an oral cavity) having magnets on bothlateral sides of the oral cavity, and further showing in thisarrangement the magnetic attracting forces that resist occurrence of thetissue condition shown in FIG. 3, involving the collapse of a tongueagainst the pharyngeal wall.

FIG. 26B is an anatomical superior view of the oral cavity, like thatshown in FIG. 25, in which the ferromagnetic structure implantedasymmetrically in the tongue interacts with a magnetic structure insidean airway (e.g., on teeth within an oral cavity) having magnets only onone lateral side of the oral cavity opposite to the asymmetricferromagnetic structure in the tongue, and further showing in thisarrangement the magnetic attracting forces that resist occurrence of thetissue condition shown in FIG. 3, involving the collapse of a tongueagainst the pharyngeal wall.

FIG. 27 is an anatomical superior view of the oral cavity, like thatshown in FIG. 25, in which the ferromagnetic structure implantedasymmetrically in the tongue interacts with a magnetic structureimplanted in a pharyngeal wall opposite to the ferromagnetic structure,and further showing in this arrangement the magnetic repelling forcesthat resist occurrence of the tissue condition shown in FIG. 3,involving the collapse of a tongue against the pharyngeal wall.

FIG. 28 is an anatomical superior view of the oral cavity, showing thetongue and pharyngeal conduit, and further showing a ferromagneticstructure implanted in a tongue, in which the ferromagnetic structureextends generally asymmetrically only on one lateral side of the tongue,but includes an appendage that is free of a ferromagnetic materialextending into the opposite lateral side of the tongue, the view alsoshowing a tissue condition as shown in FIG. 3, involving the collapse ofa tongue against the pharyngeal wall.

FIG. 29A is an anatomical superior view of the oral cavity, like thatshown in FIG. 28, in which the ferromagnetic structure implantedasymmetrically in the tongue with a non-ferromagnetic appendageinteracts with a magnetic structure inside an airway (e.g., on teethwithin an oral cavity) having magnets on both lateral sides of the oralcavity, and further showing in this arrangement the magnetic attractingforces that resist occurrence of the tissue condition shown in FIG. 3,involving the collapse of a tongue against the pharyngeal wall.

FIG. 29B is an anatomical superior view of the oral cavity, like thatshown in FIG. 28, in which the ferromagnetic structure implantedasymmetrically in the tongue with a non-ferromagnetic appendageinteracts with a magnetic structure inside an airway (e.g., on teethwithin an oral cavity) having magnets only on one lateral side of theoral cavity opposite to the asymmetric ferromagnetic structure in thetongue, and further showing in this arrangement the magnetic attractingforces that resist occurrence of the tissue condition shown in FIG. 3,involving the collapse of a tongue against the pharyngeal wall.

FIG. 30 is an anatomical superior view of the oral cavity, like thatshown in FIG. 28, in which the ferromagnetic structure implantedasymmetrically in the tongue with a non-ferromagnetic appendageinteracts with a magnetic structure implanted in a pharyngeal wallopposite to the ferromagnetic structure, and further showing in thisarrangement the magnetic repelling forces that resist occurrence of thetissue condition shown in FIG. 3, involving the collapse of a tongueagainst the pharyngeal wall.

FIGS. 31A and 31B are, respectively, a perspective view and a top viewof a representative embodiment of an asymmetric ferromagnetic structurehaving a non-ferromagnetic appendage that includes a non-ferromagneticrudder-type structure to further stabilize the structure and move moretissue in response to magnetic interaction of a magnetic structurewither inside or outside the airway, or both.

FIG. 31C is an anatomical superior view of the oral cavity, showing thetongue and pharyngeal conduit, and further showing the ferromagneticstructure shown in FIGS. 31A and 313 implanted in a tongue, the viewalso showing a tissue condition as shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIG. 31D is an anatomical superior view of the oral cavity, like thatshown in FIG. 31C, in which the ferromagnetic structure shown in FIG.31C interacts with a magnetic structure inside an airway (e.g., on teethwithin an oral cavity) having magnets only on one lateral side of theoral cavity opposite to the asymmetric ferromagnetic structure in thetongue, and further showing in this arrangement the magnetic attractingforces that resist occurrence of the tissue condition shown in FIG. 3,involving the collapse of a tongue against the pharyngeal wall.

FIGS. 32A and 32B are, respectively, a perspective view and a top viewof a representative embodiment of a magnetic structure having oppositearm regions of opposite magnetic polarity and an intermediatenon-magnetic rudder-type structure to further stabilize the structureand move more tissue in response to magnetic interaction of a magneticstructure wither inside or outside the airway, or both.

FIG. 33 is an anatomical superior view of the oral cavity, showing thetongue and pharyngeal conduit, and further showing the ferromagneticstructure shown in FIGS. 32A and 32B implanted in a tongue, the viewalso showing a tissue condition as shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIGS. 34A and 34B are anatomical superior views of the oral cavity, likethat shown in FIG. 33, in which the ferromagnetic structure shown inFIG. 33 interacts with a magnetic structure inside an airway (e.g., onteeth within an oral cavity) having magnets only on one lateral side ofthe oral cavity, and further showing in this arrangement the magneticattracting forces that resist occurrence of the tissue condition shownin FIG. 3, involving the collapse of a tongue against the pharyngealwall.

FIG. 35 is an anatomical superior view of the oral cavity, like thatshown in FIG. 33, in which the ferromagnetic structure shown in FIG. 33interacts with a magnetic structure implanted in a pharyngeal wallopposite to the ferromagnetic structure, and further showing in thisarrangement the magnetic attracting and repelling forces that resistoccurrence of the tissue condition shown in FIG. 3, involving thecollapse of a tongue against the pharyngeal wall.

FIG. 36 is an anatomic sagittal view of the tongue, soft palate/uvula,and pharyngeal wall, showing the resolution of forces F-sep and F-nat toprovide an optimal therapeutic force F-mag that, at night, resistscollapse of the tongue against the pharyngeal wall during sleep, yetdoes not affect speech, swallowing or drinking during normal activitiesawake or asleep.

FIG. 37 is an anatomic sagittal view of the tongue, soft palate/uvula,and pharyngeal wall, showing the resolution of forces F-sep and F-nat toprovide an optimal therapeutic force F-mag that, at night, resistscollapse of the soft palate/uvula against the pharyngeal wall duringsleep, yet does not affect speech, swallowing or drinking during normalactivities awake or asleep.

FIG. 38 is a chart executing an implant force scaling strategy.

FIGS. 39A and 39B are anatomic side section views of the upper airway ofa human, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing arepresentative magnetic force system of a type shown in FIG. 4Ccomprising a ferromagnetic structure implanted in a lower, inferiorregion of a tongue that interacts with a magnetic structure carriedoutside an airway (e.g., on a jaw), to resist occurrence of the tissuecondition shown in FIG. 3, involving the collapse of a tongue againstthe pharyngeal wall, the ferromagnetic structure including (in FIG. 39A)a single tethered anchoring assembly and (in FIG. 39B) a multiple tetheranchoring assembly to stabilize the ferromagnetic structure in closeproximity to the external jaw-mounted magnetic structure.

FIGS. 39C and 39D are anatomic side section views of the upper airway ofa human, showing the nasal and oral cavities, tongue, hard palate, softpalate, oral pharynx, chin and neck, and further showing anotherrepresentative tethered magnetic force system of a type shown in FIGS.40A and 40B, comprising a ferromagnetic structure implanted in a moreanterior region of a tongue that interacts with a magnetic structurecarried outside an airway (e.g., on a chin), to resist occurrence of thetissue condition shown in FIG. 3, involving the collapse of a tongueagainst the pharyngeal wall, the ferromagnetic structure including (inFIG. 39C) a single tethered anchoring assembly and (in FIG. 39D) amultiple tether anchoring assembly to stabilize the ferromagneticstructure in close proximity to the external chin-mounted magneticstructure.

FIG. 39E is a perspective view of a representative tether anchoringassembly that includes an umbrella-like anchor that collapses forimplantation and expands in situ within the implantation site.

FIG. 39F is a perspective view of a representative tether anchoringassembly that is adjustable and lockable to adjust and control tension.

FIGS. 40A to 40C show representative embodiments of a ferromagneticstructure implanted in an anterior or caudal anterior region of atongue, or in the myohyoid muscle, in proximity to external magneticstructures, e.g., a mouthpiece carried within the oral cavity or anexternal carrier placed on or under the chin or about the neck.

FIGS. 41A and 41B show devices that consist of one or more ferromagneticstructure(s) attached to one or more elastic components sized andconfigured to deflect under load in a prescribed manner and to recoveran initial shape when unloaded.

DETAILED DESCRIPTION

This specification discloses various magnetic implants and externaldevices, systems, and methods for the use of attracting magnetic forceto maintain a patent airway. For example, the various aspects of theinvention have application in procedures requiring the restriction oftissue collapse in and/or around the body, such as a passageway withinthe body. The devices, systems, and methods that embody features of theinvention are also adaptable for use with devices, systems, and methodsthat are not restricted to tissue based applications.

The devices, systems, and methods are particularly well suited fortreating sleep disordered breathing, including sleep apnea. For thisreason, the devices, systems, and methods will be described in thiscontext. Still, it should be appreciated that the disclosed devices,systems, and methods are applicable for use in treating otherdysfunctions elsewhere in the body, which are not necessarily sleepdisorder related.

I. THE TONGUE AND THE SOFT PALATE

A. Anatomy

FIG. 2 shows an anatomical view of the oral cavity, where the tongue hasbeen pulled towards the front. FIG. 2 shows the tongue and the roof ofthe mouth, i.e., the palate, as previously described and as also shownin FIG. 1. FIG. 2 shows the two parts of the palate which have also beenpreviously described: namely, the hard palate (in the front) and thesoft palate (in the back).

The hard palate is bounded in the front and laterally by the alveolararches and gums and in the back by the soft palate. A dense structuremade up by the periosteum and the mucous membrane of the mouth coversthe hard palate. The linear raphé lies along the middle line of the hardpalate.

The soft palate is a movable fold, suspended from the posterior borderof the hard palate and forms an incomplete dividing line (septum)between the mouth and the pharynx. The soft palate comprises a mucousmembrane that envelops muscular fibers, an aponeurosis, vessels, nerves,adenoid tissue, and mucous glands.

When the soft palate is relaxed and hanging, the anterior surface isconcave and follows the same line as the roof of the mouth. Theposterior surface of the soft palate is convex and is a continuance ofthe mucous membrane that covers the bottom part of the nasal cavities.The upper boundary of the soft palate attaches to the hard palate; thesides become part of the pharynx; and the lower boundary is free. Thelower boundary which hangs down, separating the mouth and the pharynx isknown as the palatine velum. In the middle of the lower boundary, thesmall, fleshy cone-shaped protuberance is called the uvula. The archesare located laterally and downwardly from the uvula. These arches arecalled the glossopalatine arch (the anterior arch) and thepharyngopalatine arch (the posterior arch). The palatine aponeurosis isa thin, firm fiber-filled lamella which gives support to the muscles andmakes the soft palate strong.

The tongue is located over the floor of the oral cavity. In human beingsthe tongue is an organ that undergoes a wide variety of movements,partly because it is involved in a broad range of activities, includingspeech, eating and swallowing. When a human is awake, the tonguenormally moves in an up and forward position. When a human is asleep,the muscles of the tongue relax and the tongue is able to move in aneven broader range of directions. This movement can occur laterally,posteriorly, anteriorly, cranially, caudally, in a rolling manner, orany combinations thereof.

During the process of eating and swallowing, the uvula prevents the foodfrom entering the nasopharynx and the muscles of the soft palate pushthe food down into the pharynx. The tongue can move in conjunction withother structures (i.e. with the tongue and pharyngeal wall comingtogether, or with the tongue and palate coming together) orindependently of other structures (i.e. tongue movement without palate,pharyngeal wall, or epiglottis movement).

B. The Tongue/Soft Palate and Sleep Apnea

Sleep apnea occurs when the airway becomes obstructed; hypopnea occurswhen the airway is partially obstructed. Sleep apnea takes many forms;closure of the airway can occur at any number of anatomical structuresalong the airway, including any combination of the tongue, soft palate,epiglottis, and pharyngeal wall. For example, the tongue may collapsewith respect to the pharyngeal wall, or both the base of the tongue andthe pharyngeal wall may collapse at the same time. Likewise, the softpalate/uvula may collapse with respect to the pharyngeal wall and/ortongue, or both the soft palate/uvula and/or tongue and/or thepharyngeal wall may collapse at the same time. Thus, sleep apnea may betreated by either preventing the collapse of the tongue, pharyngealwall, soft palate/uvula independently, and/or one or more of the tonguebase, the pharyngeal wall, and/or the soft palate/uvula at the sametime.

FIG. 1 is an anatomical side view of the upper airway system in a normalpatient, showing the nasal and oral cavities, tongue, hard palate, softpalate, oropharynx, chin and neck. FIG. 3 shows an anatomical side viewof a patient suffering from one form of sleep apnea involving at thesame time the tongue, the pharyngeal wall, and the soft palate/uvula. Asshown in FIG. 3, the tongue base, the soft palate, and the uvula leanagainst the pharyngeal wall, effectively closing off the airway. Anapneic episode can occur as a result.

II. ATTRACTING MAGNETIC FORCE SYSTEMS

A. Overview

1. Resisting Collapse of the Tongue (The Tongue System)

FIGS. 4A to 4D show in a diagrammatic way representative embodiments ofa magnetic force system 10 a that resists, at least in part, the tissuecondition shown in FIG. 3, involving the collapse of the tongue againstthe pharyngeal wall. This system 10 a in its various embodiments will bein shorthand called the Tongue System. The Tongue System 10 a includesone magnetic structure 12 and one magnetic structure 14 to create anattracting magnetic force between the two structures, which maintainsthe tongue in a position spaced away from the posterior pharyngeal wall,as FIGS. 4A, 4B, 4C, and 4D show. The magnetic force field resistsposterior movement of the tongue during sleep, keeping the airway open.An apneic episode is avoided.

In the representative embodiments shown in FIGS. 4A and 4B, the magneticstructure 12 is positioned in or on the tongue. More specifically,magnetic structure 12 can be positioned either in the anterior or in theposterior region of the tongue. In FIG. 4A, the magnetic structure 14,which the magnetic structure 12 interacts with, is positioned outsidethe airway (e.g., on the chin), whereas in FIG. 4B, the magneticstructure 14 is positioned within the airway (e.g., in the oral cavity).

In the representative embodiments shown in FIGS. 4C and 4D, the magneticstructure 12 is positioned in the general area between the mandible andthe hyoid bone, either in or on the hyoid muscles (e.g. one or more ofthe suprahyoid muscles such as the mylohyoid muscles, the geniohyoidmuscles, or the stylohyoid muscles, or the digastric muscles), or underthe skin. In FIG. 4C, the magnetic structure 14, which the magneticstructure 12 interacts with, is positioned outside the airway (e.g., onthe chin), whereas in FIG. 4D, the magnetic structure 14 is positionedwithin the airway (e.g., in the oral cavity).

2. Resisting Collapse of the Soft Palate (The Soft Palate System)

FIGS. 5A and 5B show in a diagrammatic way representative embodiments ofa magnetic force system 10 b that resists, at least in part, the tissuecondition shown in FIG. 3, involving the collapse of the softpalate/uvula against the pharyngeal wall. This system 10 b in itsvarious embodiments will be in shorthand called the Soft Palate System.The Soft Palate System 10 b includes one magnetic structure 12 and onemagnetic structure 14 to create a magnetic force field, which maintainsthe soft palate/uvula in a position spaced away from the posteriorpharyngeal wall, as FIGS. 5A and 5B show. The magnetic force fieldresists posterior movement of the soft palate/uvula during sleep,keeping the airway open. An apneic episode is avoided.

In the representative embodiments shown in FIGS. 5A and 5B, the magneticstructure 12 is positioned in or on the soft palate/uvula. In FIG. 5A,the magnetic structure 14, which the magnetic structure 12 interactswith, is positioned outside the airway (e.g., on the chin), whereas inFIG. 5B, the magnetic structure 14 is positioned within the airway(e.g., in the oral cavity).

3. Resisting Collapse of the Tongue and the Soft Palate (The CombinedSystem)

FIGS. 6A and 6B show in a diagrammatic way representative embodiments ofa magnetic force system 10 c that resists, at least in part, the tissuecondition shown in FIG. 3, involving the collapse of both the tongue andthe soft palate/uvula against the pharyngeal wall. This system 10 c inits various embodiments will be in shorthand called the Combined System.The Combined System 10 c includes two magnetic structures 12 a and 12 band one magnetic structure 14 to create a magnetic force between thetwo, which maintains both the tongue and the soft palate/uvula in aposition spaced away from the posterior pharyngeal wall, as FIGS. 6A and6B show. The magnetic force field resists posterior movement of both thetongue and the soft palate/uvula during sleep, keeping the airway open.An apneic episode is avoided.

In the representative embodiments shown in FIGS. 6A and 6B, the magneticstructure 12 a is positioned in or on the soft palate/uvula and themagnetic structure 12 b is positioned in or on the posterior (back) ofthe tongue. In FIG. 6A, the magnetic structure 14, which the magneticstructures 12 a and 12 b interact with, is positioned outside the airway(e.g., on the chin), whereas in FIG. 6B, the magnetic structure 14 ispositioned within the airway (e.g., in the oral cavity). It should beappreciated that the magnetic structure 12 b can, alternatively, bepositioned in the general area between the mandible and the hyoid bone,either in or on the muscles (e.g. mylohyoid, geniohyoid, or digastric),or under the skin, in the manner shown in phantom lines in FIGS. 6A and6B, in the manner previously shown in FIGS. 4C and 4D).

B. Placement of the Ferromagnetic Structures

The magnetic force systems 10 a, 10 b, and 10 c can be variouslyconstructed. In the illustrated arrangements, all the force systems 10a, 10 b, and 10 c include in their most basic form the two structures 12and 14. One structure 12 is placed in or on tissue that is relativelymobile and subject to collapse, if not restrained from doing so. Theother structure 14 is placed in or on tissue that is, relativelyspeaking, immobile, relative to the direction of collapse.

The structures 12 and 14 comprise ferromagnetic materials. Theferromagnetic materials of the structures 12 and 14 are sized, selected,and arranged to magnetically interact by developing between thestructures 12 and 14 a magnetic force. The magnetic force includes atleast one vector or component that magnetically attracts the structure12 in or on the mobile tissue toward the structure 14 in or on therelatively immobile tissue. Posterior movement or other movement whichcould lead to an apneic or hypopneic obstruction or narrowing of therelatively mobile tissue is thereby resisted.

1. The First Structure

The first structure 12 is internally placed in or on the relativelymobile tissue in the airway targeted for treatment. In the Tongue System10 a (FIGS. 4A to 4D), the targeted tissue is tongue tissue, and, inparticular, tissue at or near the posterior part (base) of the tongueacross from the pharyngeal wall (FIGS. 4A and 4B) or in the general areabetween the mandible and the hyoid bone, either in or on the muscles(e.g. mylohyoid, geniohyoid, or digastric), or under the skin (FIGS. 4Cand 4D). In the Soft Palate System 10 b (FIGS. 5A and 5B) the targetedtissue is the soft palate/uvula across the airway from the pharyngealwall. In the Combined System 10 c (FIGS. 6A and 6B), the targeted tissueis both tongue tissue (or, alternatively, in the general area betweenthe mandible and the hyoid bone, either in or on the muscles (e.g.mylohyoid, geniohyoid, or digastric), or under the skin) and the softpalate/uvula across the airway from the pharyngeal wall.

Due to its interior placement, the ferromagnetic structure 12 isdesirably sized and configured for relatively long-term placement orimplantation in tissue.

2. The Second Structure

As previously described, the second structure 14 can be placed eitherexternally in or on relatively immobile tissue outside the airway orinternally in or on relatively immobile tissue within an airway. Thestructure 14 is placed to magnetically interact with the structure 12 bydeveloping between the ferromagnetic materials on the structures 12 and14 a magnetic force that includes at least one vector or component thatmagnetically attracts the structure 12 in or on the mobile tissue towardthe structure 14 in or on the relatively less mobile tissue.

In the Tongue System 10 a (FIGS. 4A to 4D), the magnetic attractingforce between the two ferromagnetic structures 12 and 14 resistsposterior or other movement of the tongue toward the posteriorpharyngeal wall. In the Soft Palate System 10 b (FIGS. 5A and 5B), themagnetic attracting force between the two ferromagnetic structures 12and the one ferromagnetic structure 14 resists posterior or othermovement of the soft palate/uvula toward the posterior pharyngeal wall.In the Combined System 10 c (FIGS. 6A and 6B), the magnetic attractingforce between the two ferromagnetic structures and ferromagneticstructure 14 resists posterior movement of both the tongue and the softpalate/uvula toward the posterior pharyngeal wall. In all systems 10 a,10 b, and 10 c, the magnetic force prevents, in whole or in part, theoccurrence of the airway-occluding tissue condition shown in FIG. 3. AsFIGS. 4A to 4D, 5A and 5B, and 6A and 6B show, the magnetic forcebetween the first and second ferromagnetic structures 12 andferromagnetic structure 14 works to keep the airway open (i.e., patent)during sleep.

Due to its placement, the ferromagnetic structure 14 is desirably sizedand configured to be removable, so that it can be temporarily placedinto association with the more permanent ferromagnetic structure 12 andthereafter removed, when desired, from the association. Thus, theferromagnetic structure 14 can be placed into association with theinternal ferromagnetic structure 12 when the presence of the magneticforce field is desired, e.g., during sleep, and can be removed at othertimes. A removable structure 14 also has the advantage of being easilyand accurately titrated (i.e. increasing or decreasing the force tooptimize the performance of the system). This titration could beaccomplished by switching different ferromagnetic materials of variousstrengths by a clinician or by the user and/or by adjusting the relativeposition or distance of the removable structure 14 with respect to theinternal structure 12.

a. External Placement

In FIGS. 4A, 4C, 5A, and 6A, the second structure 14 is shown placed onrelatively immobile tissue externally outside the airway. Moreparticularly, in FIGS. 4A, 4C, 5A, and 6A, the second structure 14 isshown placed externally on or under the chin or lower jaw. Various waysof placing the structure 14 in this position are possible.

For example, as shown in FIG. 7A, the external ferromagnetic structure14 can be shaped, sized and configured as a carrier 28 that can besecured at the level of the mandibular joint by, e.g., headgear thatincludes a strap 32 that fits over the head. As will be described ingreater detail later, the carrier 28 includes an array of one or moreferromagnetic materials 26 positioned and arranged to attract theferromagnetic materials in the internal structure 12 positioned in or onthe tongue, the soft palate/uvula, or both.

Alternatively, as FIG. 7B shows, the carrier 28 of the externalferromagnetic structure 14 can be shaped to include a cup 34 that fitsover the chin, to add further stability and comfort. In thisarrangement, the headgear strap 32 attaches to the carrier 28 at thelevel of the mandibular joint, as well as to the chin-cup 34, helping toimmobilize the position of the headgear.

As FIG. 7C shows, the carrier 28 can be shaped, sized, and configured asa chin cup 34 that includes an extension, which extends a measuredminimum distance (e.g., at least 4 cm) under the chin below the tongue.In this arrangement, the extension carries at least one ferromagneticmaterial 26, which interacts with the ferromagnetic materials in theinternal structure 12 positioned in or on the tongue. In this embodimentthe headgear strap 32 can fit over the head and attach to both the chincup and its extension under the chin. This embodiment is particularlyuseful when the therapeutic objective is to principally targetresistance to posterior movement of the tongue.

In an alternative arrangement, the second structure 14 can be placedaround the neck. As shown in FIG. 8A, the second structure 14 comprisesa carrier 28 that includes an array of one or more ferromagneticmaterials 26. The carrier 28 includes a neck collar 38, which serves toposition and orient the ferromagnetic materials 18 to attract theferromagnetic materials in the internal structure 12 positioned in or onthe tongue, the soft palate/uvula, or both.

In the embodiment shown in FIG. 8B, an anterior part of the neck collarthat fits under the chin is higher than the posterior part that fitsunder the back of the head. This configuration raises the level of thechin and serves to extend the neck, by tilting the head back and raisingthe chin. The embodiment shown in FIG. 8B mimics the extension of theneck accomplished during CPR. The extension may add a mechanicalenhancement to the magnetic force field, helping to maintain or furtheropen up the airway.

Benefits of using external magnetic devices include: (1) larger andstronger magnets may be used than could be either implanted or affixedto an appliance worn in the mouth (as will be described in greaterdetail later); (2) external devices are easily removed, so that theforce delivered need only be experienced when the patient wishes tosleep, and not during eating or speech thus minimizing the effect ofmagnetic force on these activities; and (3) without need for surgicalintervention, the amount and direction of the magnetic forces can bechanged. This is accomplished by exchanging magnet types and sizes andby changing the location of the magnets within the external device.

b. Internal Placement

Alternatively, the second structure 14 can be placed in or on relativelyimmobile tissue internally inside the airway, e.g., within an oralcavity in proximity to the first structure 12 (which is desirably placedin or on a tongue and/or soft palate/uvula). For example (as FIGS. 9A,9B, 9C, 9D, and 9E show), the second structure 14 can be shaped, sizedand configured to be fitted inside the mouth in various positions alongthe inner or outer edge of the lower teeth or covering the top of thelower or upper teeth, the second structure also comprising magneticmaterials that are generally aligned with, on top of, or below thetongue. The structure could, in principle, also be placed on the upperteeth.

For example, in FIG. 9A, the second ferromagnetic structure 14 comprisesa carrier 28 that takes the form of a mouthpiece 40 that fits along theinside edge of the lower teeth. An array of one or more ferromagneticmaterials 26 is carried by the carrier 28, as will be described ingreater detail later. In the illustrated embodiment, the mouthpiece 40attaches to the lower teeth in a suitable manner, e.g., with the hooks42 as shown.

FIG. 9B shows an alternative arrangement. In this arrangement, thesecond ferromagnetic structure 14 comprises a carrier 28 that takes theform of a mouthpiece 40 that fits along the outside edge of the lowerteeth in a suitable manner, e.g., the two hooks 42 as shown. An array ofone or more ferromagnetic materials 26 is carried by the carrier 28, aswill be described in greater detail later.

FIG. 9C shows another alternative arrangement. In this arrangement, thesecond ferromagnetic structure 14 comprises a carrier 28 that takes theform of a mouthpiece 40 that is pre-formed by molding to fit and coverthe lower teeth. An array of one or more ferromagnetic materials 26 iscarried by the carrier 28, as will be described in greater detail later.

FIGS. 9D and 9E are other alternative embodiments of the mouthpiece 40of the type shown in FIG. 9C, which fit over the lower teeth. In FIGS.9D and 9E, the mouthpiece includes one or more protrusions 43 thatextend medially from the teeth into the oral cavity. In FIG. 9D, the oneor more protrusions extend over the tongue. In FIG. 9E, the one or moreprotrusions 43′ extend beneath the tongue. The protrusions carry anarray of one or more ferromagnetic materials 26. In this way, theferromagnetic materials 26 can be placed in close superior alignment(FIG. 9D) or inferior alignment (FIG. 9E) with the ferromagneticmaterials 26 in the first structure 12 in the tongue, and/or in closeinferior alignment with the ferromagnetic materials 26 in the firststructure 12 in the soft palate/uvula.

Alternative embodiments to the mouthpieces 40 shown in FIGS. 9A to 9Dare also envisioned where the carrier 28 fits over the upper teeth.

The configuration and placement of the various mouthpieces 40 in FIGS.9A, 9B, 9C, 9D, and 9E physically locate the ferromagnetic materials 26of the second ferromagnetic structure 14 in relatively close proximityto a ferromagnetic structure 12 placed in or on the tongue and/or softpalate/uvula. The proximity increases the magnitude of the magneticfield within the airway necessary to achieve the desired therapeuticeffect. Thus, the proximity makes possible the use of relatively smallerferromagnetic materials in both structures 12 and 14, when compared toan external second magnetic structure in a collar, head gear or otherlocation.

C. Configuration of the Ferromagnetic Structures

As seen in FIG. 10, in its most basic form, the magnetic structures 12and 14 of the magnetic force system 10 each comprises at least oneferromagnetic material. The ferromagnetic material(s) of the magneticstructure 12 will be identified by reference number 16, theferromagnetic material(s) for the magnetic structure will be identifiedby reference number 18. The ferromagnetic materials 16 of the firststructure 12 are placed in or on the targeted tissue regions (tongueand/or soft palate/uvula). The ferromagnetic materials 18 of the secondstructure 14 are placed under the chin, the lower jaw, along the inneror outer edge of the lower teeth, or on top of the lower teeth, alongthe inner or outer edge of the upper teeth, or beneath the upper teeth.The ferromagnetic materials 16 and 18 of the magnetic structures 12 and14, forming the force systems 10 a, 10 b, and 10 c are placed tomagnetically interact and stabilize the tongue and/or soft palate/uvula,thereby resisting the collapse of tissue in the airway between thetongue and/or soft palate/uvula and the pharyngeal wall during sleep.

1. Orientation of Magnetic Poles

Each ferromagnetic material 16 and 18 can comprise a permanent magnet. Apermanent magnet is characterized as a material showing resistance toexternal demagnetizing forces once being magnetized. That is, a highexternal magnetic field is required in order to remove the residualmagnetism of a permanent magnet. Stated differently, a permanent magnethas very high intrinsic coercivity, which is a measure of its resistanceto demagnetization.

A permanent magnet possesses poles of opposite polarity. The poles areregions of a magnet (usually at the end of the magnets) where theexternal magnetic field is strongest. Relative to Earth's magneticpoles, if the magnet is free to turn, one pole will point to themagnetic north pole of the Earth, and is thus called a north pole of themagnet, which is indicated by N in the drawings or otherwise called aN-pole. The opposite pole is called a south pole of the magnet, which isindicated by S in the drawings or otherwise called an S-pole.

According to physical laws, poles of like polarity (N-N or S-S) repeleach other with a magnetic force. Conversely, poles of unlike polarity(N-S or S-N) attract each other with a magnetic force. Thus, structures1 i and 14 incorporating permanent magnets will repel each other whenlike poles of the structures 12 and 14 (N-N or S-S) are oriented to faceeach other, and likewise attract each other when opposite poles of thestructures 12 and (N-S or S-N) are oriented to face each other. Themagnitude of the force of magnetic attraction or repulsion depends onthe strength of the magnets and the distance between the poles.

Examples of known permanent magnet materials include alloys ofNeodymium-Iron-Boron (NdFeB), alloys of Aluminum-Nickel-Cobalt (AlNiCo),and Samarium Cobalt (SmCo). An electromagnet (current flowing through acoil of wire) can be substituted for a permanent magnet.

In the magnetic force systems 10 a, 10 b, and 10 c shown in,respectively, FIGS. 4A to 4D, 5A and 5B, and 6A and 6B the magneticmaterials 16 and 18 are oriented such that opposite poles (N-S or S-N)generally face each other across lower jaw or across tongue tissue.Thus, the first and second magnetic structures 12 and 14 are referred toas having opposite polarities. The structures 12 and 14 willmagnetically interact by the generation of a magnetic force betweenthem. The nature of the magnetic force will generally be called inshorthand for purposes of description an “attracting” magnetic force,because it involves an interaction between magnetic poles of the unlikepolarities. However, it should be appreciated that the magnetic forcegenerated between the structures 12 and 14 can include a torquing force(i.e., a force or moment of a force that tends to rotate the internalstructure 12 in the more mobile tissue of the tongue and/or softpalate/uvula about an axis), and/or a decentering force (i.e., a forcein essentially a lateral or side-to-side direction that tends to offsetthe internal structure 12 in the tongue and/or soft palate/uvula left orright, again depending the mobile tissue region being targeted), or acombination of two or more attracting, torquing, and decentering forces.One or more of these magnetic forces collectively can prevent the tongueand/or soft palate (depending on the mobile tissue region beingtargeted) from moving in a posterior direction and closing, obstructing,or restricting the pharyngeal conduit or airway. One of the predominantadvantages of the attracting systems is their ability to decrease oreliminate the significant and problematic decentering and torquingforces seen in repelling magnetic systems in treating OSA.

It should be appreciated that the structure 12 in the more mobiletargeted tissue region can include a ferromagnetic material 16 that isitself not magnetized, but that nevertheless is attracted to aferromagnetic material 18 on the structure 14 in the less mobiletargeted tissue region, which is magnetized. Therefore, theferromagnetic material(s) 16 of the structure 12 can comprise anun-magnetized material, e.g., ferrous plate, on which the magnetizedferromagnetic material 18 of the structure 14 exerts an attractivemagnetic force. The terms “ferromagnetic” material as used in thisspecification is therefore not necessarily limited to an object thatexhibits magnetic properties (i.e., an object that is magnetized), butalso encompasses an object made of a material that is not itselfmagnetized but which is attracted to another object that is magnetized.

2. Magnetic Structures

As previously described in general terms, the ferromagnetic material 16of the first structure 12 can be magnetized or un-magnetized. However,it is desirably permanently magnetized and therefore will be describedas “magnetic”. The magnetic material 16 is placed in or on tissue in theairway. The term placed “in or on” is intended to mean that the magneticmaterial 16 can be placed either on surface tissue or implanted withintissue. For longevity and comfort, the material 16 is desirablyimplanted within tissue. In the illustrated embodiments, the targetedtissue can comprise a region of the tongue, a region of the softpalate/uvula, or both.

As previously generally described, the ferromagnetic material 18 of thesecond structure 14 is also desirably permanently magnetized andtherefore will be described as “magnetic”. The magnetic material 18 isplaced externally of the airway under the chin or lower jaw, orinternally within the airway along the inner or outer edge of the lowerteeth, on top of the teeth, or on top of or below the tongue. Aspreviously described, when externally located, the magnetic material 18is desirably mounted or carried in an individually fitted chin strap orneck collar. When internally located, the magnetic material 18 isdesirably mounted or carried in an oral mouthpiece fitted to the lowerteeth. In this way, the magnetic material 18 can be located externallyunder the lower jaw, or internally along the inner or outer edge of thelower teeth, on top of the lower teeth, on top of or below the tongue tomagnetically interact with the material 16 placed on or implanted withintissue in a region of the tongue, a region of the soft palate/uvula, orboth.

The permanent magnetic materials 16 and 18 can each be configured invarious ways and take various shapes, e.g., cylindrical, square,rectangular, or other polygons. A given magnetic material 16 or 18 of agiven internal component, implant 12 or external component 14 cancomprise a single or discrete source of magnetism having a given desiredpolar orientation. For example, a given magnetic material 16 or 18 cancomprise a single permanent magnet, as shown in FIG. 10. Bondedpermanent magnets may also be used. Bonded magnets can be flexible orrigid, and consist of powdered NdFeB, Ferrite, or SmCo permanent magnetmaterials bonded in a flexible or rigid substrate of e.g., rubber,nitrile, polyethylene, epoxy, polyvinyl chloride, silicone, rubber, ornylon. The forming of the bonded magnet can be achieved by extrusion,compression molding, injection molding, calendering, or printing. Bondedmagnets enable unique flexible designs, and durable high toleranceshapes that are otherwise difficult to achieve.

Alternatively, a plurality of permanent magnetic material 16 or 18 canbe positioned for placement as an array 22 carried as a unit on asupport carrier 24, or otherwise directly linked together, as shown inFIG. 11. The carrier 24 can comprise, for example, a woven, formed, ormolded structure made, e.g., from a polymer or fiber or fabric ornon-ferrous metallic material. Like the magnetic materials 16/18themselves, the arrays 22 can be variously shaped, sized, and configuredfor implantation in the intended tissue region (for the first structure12) or for placement in association with external or internal tissue(for the second structure 14).

In the arrangement shown in FIG. 11, the magnetic materials 16/18 areplaced on the carrier 24 with the N and S-poles facing generally in thesame direction. In FIG. 11, the N-pole orientation is shown by thearrows, and the S-pole is therefore oriented in an opposite direction.In this way, an array 22 of like permanent magnets 16/18 having therelatively similar magnetic orientation (i.e., polarity) can beassembled for orientation as a unit on the carrier 24.

With respect to the first structure 12, a plurality of permanentmagnetic materials 16 (or un-magnetized materials that are attracted toa magnetic material) can be incorporated within a flexible or compliantarray 22 and carried as a unit on a support carrier 24 (as shown in FIG.11) for implantation in tissue. With respect to the second structure 14(the arrangements shown in FIG. 7A to 7C; FIGS. 8A and 8B; and FIGS. 9Ato 9E), a plurality of permanent magnetic materials 18 can beincorporated in a more rigid array 26 carried as a unit on a supportcarrier 28. The support carrier 28 can be individually associated withheadgear to stabilize its placement on or under the chin (FIGS. 7A to7C), with a neck piece to stabilize its placement about a neck (FIGS. 5Aand 8B), or with a mouthpiece to stabilize its placement within an oralcavity (FIGS. 9A to 9E). Like the magnetic materials 16/18 themselves,the array 26 can be variously shaped, sized, and configured.

In either arrangement (individually as shown in FIG. 10 or on an arrayas shown in FIG. 11), the magnetic material(s) 16 or 18 is/are desirablycoated, plated, encapsulated, or deposited prior to placement in or ontissue, or placement in the respective stabilization device (headgear,neck piece, or mouthpiece) with a selected protective material 20 or 30,respectively. The protective material 20/30 is selected to provide acorrosion resistant and biocompatible interface, to prevent interactionbetween the magnetic material 16/18 and tissues or fluids of the body.The protective material 20/30 is also desirably selected to form adurable tissue interface, to provide longevity to the system component,and thereby provide resistance to structural fatigue and/or failure.

Selected to provide these desired physical and physiologic benefits, theprotective material 20 and its application to the material 16 is alsodesirably selected to avoid imparting added stiffness to the structure12 itself, to complement its preferred placement by implantation intissue. However, with respect to the structure 14 (which desirably isnot intended to be implanted), the protective material 30 used onmaterial 18 can be and is desirably selected so that it will addstiffness to structure 14, so as to maximize the attraction between arelatively flexible structure 12 and a relatively immobile and lessflexible structure 14. The more efficient the attraction betweenmaterials 18 and 16 is, the smaller the size of ferromagnetic materials16 and 18, and thus the lighter and more comfortable the structures 12and 14, can be.

The protective material 20/30 can be selected among various types ofmaterials known to provide the desired biocompatibility, resistance tocorrosion, and durability. For example, the protective material 20/30can comprise titanium or other metal material plated, deposited, orotherwise coated upon the magnetic material 16/18. As another example,the protective material 20/30 can comprise a parylene coating. As otherexamples, the protective material 20/30 can comprise a silicone polymer,a non-toxic epoxy, a medical grade polyurethane, or a U.V. curablemedical acrylic co-polymer. The protective material 20/30 may alsoincorporate anticoagulants and/or antibiotics and/or tissue in-growthpromoters.

D. Representative Systems of Magnetic Structures

1. The Tongue System

FIG. 12A shows a representative Tongue System 10 a of the type shown inFIG. 4A. The system 10 a comprises the ferromagnetic materials 16 and 18arranged in a relatively similar, attracting orientation, as previouslydescribed. In FIG. 12A, the Tongue System 10 a includes a first magneticimplant 12 comprising a first magnetic array 22 of a type shown in FIG.11 sized and configured for implantation in the tongue. The TongueSystem 10 a also includes a second magnetic component 14 comprising asecond magnetic array 26 also of a type shown in FIG. 11, but furtherincorporated into an under-the-chin orientation of a type shown in FIG.7C.

As shown in FIG. 12B, the array 22 of the first structure 12 comprises acarrier 24, on which the array 22 of ferromagnetic material(s) 16(desirably comprising one or more permanent magnets) is arranged. AsFIGS. 12A and 12B show, the carrier 24 is shaped along a longitudinalaxis to have a length that is longer than its width. Thelongitudinally-shaped array 22 is sized and configured to be implantedalong the anterior-to-posterior axis of the tongue and the airway,respectively. As shown in FIGS. 12A and 12B, the longitudinal axis ofthe array 22 extends along the raphe of the tongue.

As shown in FIG. 12C, the array 26 of the second structure 14 comprisesa carrier 28, on which the array 26 of magnetic materials 18 (alsopermanent magnets) is arranged. The carrier 28 comprises the chin cupshown in FIG. 7C. In FIG. 12C, the array 26 is horseshoe-shaped(although many other arrangements are envisioned). The horseshoe-shapedarray 26 is placed under the chin and lower jaw. It can be appreciatedthat a relatively similar or the same orientation of the magneticmaterials 18 can be achieved by placing the array 26 in association witha neck piece (as shown in FIGS. 8A and 8B) or by placing the array inassociation with a mouthpiece worn within the oral cavity (as shown inFIGS. 9A to 9E).

As shown in FIG. 12C, the horseshoe-shaped array of magnetic materials18 follows the entire curved anatomy of the oral cavity from posteriorto anterior. The array comprises posterior magnetic regions 18 a(located on opposite sides of the tongue), an anterior magnetic region18 c (located along the curved anterior region of the oral cavity), anda middle magnetic regions 18 b (located between the anterior andposterior regions of the oral cavity on opposite sides of the tongue).FIG. 12D shows an alternative embodiment to the horseshoe-shaped array.In this embodiment the magnetic materials 18 are placed both under thechin 18 a, 18 b, and 18 c, and adjacent to the chin 18 d.

When implanted, as FIG. 12E shows, poles of the magnetic material 16 ofthe first implant 12 are oriented to generally align with the oppositepoles of the magnetic material 18 of the external component 14 acrossthe airway, that is, either N-S or S-N-poles are generally alignedacross the lower jaw or across tongue tissue, in the case of themouthpiece array. As a result the magnetic external component 14interacts by attracting the magnetic tongue implant 12 (as indicated bythe facing arrows A in FIG. 12E). Due to the attracting forces A betweenimplant 12 and structure 14, the tongue tissue cannot collapse againstthe pharyngeal conduit during sleep and thus the airway remains patent.However, when an apnea patient is awake, the forces may be overcome byswallowing, speech, coughing, sneezing, etc. Alternatively, the externalmagnets 18 can be positioned and worn only for purposes of sleepingallowing for higher, more therapeutic forces during sleep which areeasily removed to allow normal swallowing and speech function duringdaytime hours.

In an alternative arrangement, as shown in FIG. 12F, the array ofmagnetic materials 18 does not symmetrically follow the entire curvedanatomy of the oral cavity from posterior to anterior. Instead, thearray comprises a posterior magnetic region 18 a, an anterior magneticregion 18 c, and a middle magnetic region 18 b asymmetrically only alongone side of the tongue. In this arrangement, in response to theattracting magnetic forces between the implant 12 implanted in thetongue and the single sided magnetic structure 14 carried by the chin,neck, or teeth, the airway on the side of the tongue farthest frommagnets 18 will open up. That side of the tongue will no longer collapseagainst the pharyngeal wall and apneic episodes will be prevented.

In yet another alternative arrangement, as shown in FIGS. 12G and 12H,the tongue implant 12′ is aligned in parallel arrangement to themouthpiece structure/external component 14. The magnetic attractingforce between the tongue implant 12′ and the external component pushesthe tongue in an anterior direction. This particular embodiment may beable to generate more force than previous embodiments due to the shorterdistance between the tongue implant and the mouthpiece structure.

2. The Soft Palate System

FIG. 13A shows a representative Soft Palate System 10 b of the typeshown in FIG. 5B. The system 10 b comprises the ferromagnetic materials16 and 18 arranged in an attracting orientation, as previouslydescribed. In FIG. 13A, the Soft Palate System 10 b includes a firstmagnetic implant 12 comprising a first magnetic array 22 of a type shownin FIG. 11 sized and configured for implantation in the soft palate. TheSoft Palate System 10 b also includes a second magnetic component 14comprising a second magnetic array 26 also of a type shown in FIG. 11,but further incorporated into a mouthpiece orientation (placed outsidethe lower teeth) of a type shown in FIG. 9B.

As shown in FIG. 13B, the array 22 of the first structure 12 comprises acarrier 24, on which the array 22 of ferromagnetic material(s) 16(desirably comprising one or more permanent magnets) is arranged. AsFIGS. 13A and 13B show, the carrier 24 is shaped along a longitudinalaxis. The longitudinally-shaped array 22 is sized and configured to beimplanted along the anterior-to-posterior axis of the soft palate andthe airway, respectively. As shown in FIGS. 13A and 13B, thelongitudinal axis of array 22 extends along the midline of the softpalate or uvula.

As shown in FIG. 13C, the array 26 of the second structure 14 comprisesa carrier 28, on which the array 26 of magnetic materials 18 (alsopermanent magnets) is arranged. The carrier 28 comprises the mouthpieceshown in FIG. 9B. In FIG. 13C, the array 26 is horseshoe-shaped toconform to the profile of the lower teeth. It can be appreciated thatthe same orientation of the magnetic materials 18 can be achieved andstabilized by placing the array 26 in association with a headgear (asshown in FIGS. 7A and 7B), chin cup (as shown in FIG. 7C), or neck piece(as shown in FIGS. 8A and 8B) or by placing the array in associationwith other mouthpieces worn within the oral cavity (as shown in FIGS. 9Aand 9C to 9E).

When implanted, as FIG. 13D shows, poles of the magnetic material 16 ofthe first implant 12 are oriented to generally align with the oppositepoles of the magnetic material 18 of the external component 14 acrossthe airway, that is, either N-S or S-N-poles are generally alignedacross tongue tissue or across the lower jaw, in the case of a chin cupor neck piece array. As a result the magnetic external component 14interacts by attracting the magnetic soft palate implant 12 (asindicated by the attracting arrows A. in FIG. 13D).

Due to the attracting force between implant 12 and structure 14, thesoft palate does not collapse against the pharyngeal conduit duringsleep and thus the airway remains patent. However, when an apnea patientis awake, the forces may be overcome by swallowing, speech, coughing,sneezing, etc. Alternatively, the oral cavity magnets 18 can bepositioned and worn only for purposes of sleeping, allowing for higher,more therapeutic forces during sleep which are easily removed to allownormal swallowing and speech function during daytime hours.

3. The Combined System

FIG. 14A shows a representative Combined System 10 c of the type shownin FIG. 6B. The system 10 c comprises the ferromagnetic materials 16 and18 arranged in an attracting orientation, as previously described. InFIG. 14A, the Combined System 10 c includes a pair of firstferromagnetic implants 12 a and 12 b. Each implant 12 a and 12 bcomprising a ferromagnetic magnetic array 22 of a type shown in FIG. 11sized and configured for implantation, respectively, in the tongue andthe soft palate. The Combined System 10 c also includes a secondmagnetic component 14 comprising a second magnetic array also of a typeshown in FIG. 11, but further incorporated into a mouthpiece orientation(placed outside the lower teeth) of a type shown in FIG. 9B.

As shown in FIGS. 14A and 14B, the arrays 22 of the first structures 12a and 12 b each comprises a carrier 24, on which the respective array 22of ferromagnetic materials 16 (desirably comprising one or moreferromagnets) is arranged. As FIGS. 14A and 14B show, the carrier 24 ofeach structure 12 a and 12 b is shaped along a longitudinal axis. Thelongitudinally-shaped array 22 of the structure 12 b is sized andconfigured to be implanted along the anterior-to-posterior axis of thetongue. The longitudinally-shaped array 22 of the structure 12 a issized and configured to be implanted along the anterior-to-posterioraxis of the soft palate.

As shown in FIG. 14C, the array 26 of the second structure 14 comprisesa carrier 28, on which the array 26 of magnetic materials 18 (alsopermanent magnets) is arranged. The carrier 28 comprises the mouthpieceshown in FIG. 9B. In FIG. 14C, the array 26 is horseshoe-shaped toconform to the profile of the lower teeth. It can be appreciated thatthe same orientation of the magnetic materials 18 can be achieved andstabilized by placing the array 26 in association with a headgear (asshown in FIGS. 7A and 7B), chin cup (as shown in FIG. 7C), or neck piece(as shown in FIGS. 8A and 8B) or by placing the array in associationwith other mouthpieces worn within the oral cavity (as shown in FIGS. 9Aand 9C to 9E).

When implanted, as FIG. 14D shows, the magnetic material 16 of bothimplants 12 a and 12 b are generally attracted to the magnetic material18 of the external component 14 (as indicated by the attracting arrows Ain FIG. 14D). Due to the attracting forces A between each of theimplants 12 a and 12 b and the structure 14, the tongue and the softpalate resist collapse against the pharyngeal conduit during sleep andthus the airway remains patent. However, when an apnea patient is awake,the forces may be overcome by swallowing, speech, coughing, sneezing,etc. Alternatively, the oral cavity magnets 18 can be positioned andworn only for purposes of sleeping allowing for higher, more therapeuticforces during sleep which are easily removed to allow normal swallowingand speech function during daytime hours.

The various magnetic force systems 10 a, 10 b, and 10 c as describedprovide an elegant, cost-effective treatment of sleep apnea. Placed inor on tissue in the tongue, soft palate, or uvula, the ferromagneticstructure 12, along with its companion ferromagnetic structure 14, iswell tolerated and significantly more comfortable and user friendly thanthe equipment of CPAP and is likely more desirable than other highlyintrusive surgical treatment options. The magnetic systems 10 a, 10 b,and 10 c offer a sophisticated, yet easy to use design, which can beshaped, configured, and magnetically titrated to meet patients'individual needs, based upon specific anatomic and physiologicrequirements, as will be described in greater detail later.

III. MODERATING THE FORCE-DISTANCE RELATIONSHIP FORCES IN DYNAMIC TISSUEREGIONS

A. Generally

In the systems 10 a, 10 b, and 10 c shown in FIGS. 12A to 12E; 13A to13D; and 14A to 14D, the magnetic components 12 and 14 are desirablyaligned vertically across the lower jaw or across tongue tissue fromeach other to create an attracting magnetic force field. In reality,there is rarely a theoretically “perfect” magnetic alignment between themagnetic materials 16 and 18. This is due to the dynamic nature of thetongue and soft palate in the airway. The distance and orientationbetween the tongue and soft palate, and between each of the tongue andsoft palate and the lower jaw varies due to patient-to-patientanatomical variability, as well as the tongue's and soft palate'sconstant movement during sleep and waking hours. There is rarely ageometrically “perfect,” parallel relationship between these tissuestructures within the airway. Further, when the tongue or soft palatemoves laterally, posteriorly, anteriorly, cranially, caudally, in arolling manner, or any combinations thereof during sleep, the movementcan significantly alter the orientation and alignment between theattracting magnetic materials 16 and 18 from one moment to another.

Variations in the force across an implant (or a magnet, or any otherobject) can manifest as torques, and are present in any magnetic systemthat is not in perfect alignment. Torque is present in all systems,whether attracting or repelling; when magnets are not in “perfect”alignment, where there is increased misalignment by angle or position,the torque will tend to correct the alignment of the magnets; i.e., theywill rotate toward an alignment that maximizes the attracting force. Themagnets want to be perfectly aligned in the highest state of attractionpossible, in other words to be best aligned with a N-pole facing aS-pole.

Magnetic structures placed in or on mobile anatomic structures in theairway are seldom, if ever, orientated in a way that permitstheoretically “perfect” or ideal alignment of N-S or S-N attractingpoles. The alignment of the attracting magnetic materials is rarelytheoretically “perfect” or ideal, and it is subject to continuouschange. It is by understanding and controlling the torque inherent inmagnetic systems, that the tongue can be effectively manipulated for thetherapeutic purposes disclosed herein.

B. Design Considerations

Any attracting magnetic system involving the tongue and/or soft palatedesirably takes into account and balances at least three considerations.One consideration is anatomic—(i) the varying distances and the lack ofperfect parallel alignment between the tongue and the soft palate andbetween each of the tongue and the soft palate and the lower jaw, due toindividual upper respiratory anatomy and the natural movement of thetongue relative to the soft palate and relative movement of either thetongue or soft palate to the lower jaw. The other two considerations arephysical—(ii) the ability to place implants in the most desiredorientation to one another; and (iii) the distance between attractingmagnets and the resulting force must also be taken into account, i.e.systems which keep distance relatively short and provide for a tether toapply force at an off-set location.

A given attracting tongue or soft palate structure should desirably bemaintained in a position of maximal attraction as other structures, suchas the tongue, soft palate, or uvula, move in relation to the lower jaw.For example, it should be recognized that during sleep, the tongue willundergo a wide variety of motions and changes of angular orientation tothe lower jaw.

A given tongue or soft palate structure desirably includes features formaintaining the implant in its close to maximal attracting state at allthe angular alignments and varying distances normally and abnormallyencountered with respect to the lower jaw, but should still allow forperformance of natural bodily functions during sleep, e.g. swallowing.

C. Titrated Magnetic Arrays

Magnetic force is roughly inversely proportional to the square of thedistance between the magnetic structures. Magnetic force is thereforevery sensitive to distance. A small increase in distance betweenattracting magnetic structures can therefore lead to a dramatic decreasein magnetic force between them. The slope of Curve SM in FIG. 15demonstrates how the magnitude of a magnetic force field (y-axis)between two single magnet structures (as shown in FIG. 10) decreasessignificantly with relatively small increases in distance between them(x-axis) due to the inverse-square relationship.

The range of distances between magnetic structures 12 and 14 in, thesystems 10 a, 10 b, and 10 c during normal anatomic functions of thetongue and/or soft palate will be in shorthand called the “workingrange.” It is believed that, in the context of the systems 10 a, 10 b,and 10 c, the working range lies in a range of about 3 cm to 4 cm. For agiven system 10 a, 10 b, or 10 c, the magnetic structures 12 and 14 aredesirably sized and configured so that the magnitude and fluxdistribution of the magnetic force field is designed or selected so thatvariations in magnetic force due to variations in distance between thestructures 12 and 14 are moderated, at least within the boundaries ofthe working range. At least within the boundaries of the working range,the titrated magnetic force field provides a variation of magnetic fieldforce with distance that presents a slope having a magnitude less thanthe slope of curve SM in FIG. 15. Again, within the boundaries of theworking range, the slope of the magnetic force field diminishessubstantially, thereby reducing the sensitivity of the force-distancerelationship. In the systems 10 a, 10 b, and 10 c shown in FIGS. 12A to12D; 13A to 13D; and 14A to 14D, the magnetic structure 14 is desirablysized and configured to provide one or more field direction(s) such thatthe magnetic structure 14 maintains a relatively constant magnetic fieldand attracting force with the internal structure 12 despite relativemovement of the tongue, soft palate, or uvula in the normal performanceof bodily functions.

During the normal performance of bodily functions, the separationbetween the centers of mass of the structures 12 and 14 will vary withinthe working range between a distance δ_(FAR) (expressed in units ofcentimeters) where the centers of mass of the structures 12 and 14 areplaced farthest apart and a distance δ_(NEAR) (expressed in units ofcentimeters) where the centers of mass of the structures 12 and 14 areplaced closest together. At the distances δ_(FAR) and δ_(NEAR) therewill be a resulting magnetic force, respectively F_(FAR) (expressed inunits of grams) and F_(NEAR) (expressed in units of grams) of themagnetic force system, which will vary roughly inversely proportional tothe square of the respective far and near distances of the workingrange, or (1/δ_(FAR) ²) and (1/δ_(NEAR) ²), respectively. The magneticstructures 12 and 14 are desirably mutually sized and configured so thatvariations in magnetic force due to various in distance between themagnetic structures 12 and 14 within the working range maintain arelationship, as follows:

(F _(NEAR) /F _(FAR))≦(δ_(FAR) ²/δ_(NEAR) ²)

In this way, the magnetic structure 14 maintains a relatively constantmagnetic field and attracting force with the internal structure 12despite relative movement of the tongue, soft palate, or uvula withinthe working range in the normal performance of bodily functions.

To achieve this objective, the systems 10 a, 10 b, and 10 c desirablyinclude magnetic structures 12 and 14 comprising arrays of magnets likethat shown in FIG. 11. Arrays of magnetic materials 16 and 18 provide amore uniform distribution of magnetic field and attracting force withthe internal structure 12 within the desired working range. Arrays ofmagnetic materials 16 and 18 also make it possible to control themagnitude and distribution of the magnetic field between the structures16 and 18 to moderate the sensitivity of the force-distance relationshipwithin the working range. Larger, smaller, or different arrays ofmagnetic materials 16 and 18 can be used to titrate the uniformattracting force with internal structure 12 and external magnet 14.

For example, the magnetic structure 14 shown in FIGS. 16A and 16Bincludes an array of magnets comprising distinct spatial magneticregions 18 a, 18 b, and 18 c having different polarities. The magneticregions 18 a, 18 b, and 18 c are sized and configured for use inassociation with an implanted magnetic structure 12 to form a TongueSystem 10 a, or a Soft Palate System 10 b, or a Combined System 10 c. InFIGS. 16A and 16B the magnetic structure 12 also comprises an array ofmagnetic regions 16 a, 16 b, and 16 c implanted in the tongue, or softpalate/uvula, or both the tongue and soft palate/uvula.

As shown in FIGS. 16A and 16B, the spatially distinct magnetic regions16 a, 16 b, and 16 c can each comprise a single magnet or an array ofindividual magnets of common polarity (as shown in FIG. 11) arranged ona carrier. The array of spatially distinct magnetic materials 16 a, 16b, and 16 c can be sized and configured to follow the curved anatomy ofthe oral cavity from posterior to anterior.

The structure 14 comprises posterior magnetic regions 18 a (located onopposite sides of the tongue), an anterior magnetic region 18 c (locatedalong the curved anterior region of the oral cavity), and a middlemagnetic region 18 b (located between the anterior and posterior regionsof the oral cavity on opposite sides of the tongue). The array ofmagnetic regions 18 a, 18 b, and 18 c shown in FIG. 16A is sized andconfigured for particular use in a chin-mounted or mouth piececonfiguration, as previously discussed and as shown, respectively, inFIGS. 7A to 7C and FIGS. 9A to 9E. The array of magnetic regions 18 a,18 b, and 18 c shown in FIG. 16B is sized and configured for particularuse in a neck piece configuration, as previously described and as shownin FIGS. 8A and 8B.

As shown in FIGS. 16A and 16B, the N-poles of the magnetic regions 18 a,18 b, and 18 c in the headgears, chin cup, mouth piece, or neck arraysare mutually oriented differently both with respect to each other andwith respect to the S-poles of the magnetic materials 16 implanted inthe airway in the tongue and/or soft palate. The mutually differentorientations of the N-poles of the magnetic regions 18 a, 18 b, and 18 cprovide a titrated magnetic field force that moderates the sensitivityof force-to-distance relationship between the magnetic materials 16 and18 in the working range.

More particularly, as FIGS. 16A and 16B show, the orientation of theN-poles of the spatially distinct magnetic regions 18 a, 18 b, and 18 cvaries from posterior to anterior with respect to the S-poles of themagnetic regions 16 a, 16 b, and 16 c. As FIGS. 16A and 16B show, theanterior magnetic region 18 c (spanning the front of the oral cavity)has a N-pole orientation directed toward the oral cavity, in a facingrelationship with the S-poles of the magnet regions 16 a, 16 b, and 16c. As the region 18 c curves to conform to the curved anatomy of theanterior oral cavity, the orientation of the N-poles of the magneticregion 18 c likewise changes to always point inwards toward the S-polesof the magnetic regions 16 a, 16 b, and 16 c. The N-S orientationbetween the anterior magnetic region 18 c of the structure 14 and theanterior magnetic regions 16 a, 16 b, and 16 c of the structure 12generates an attracting magnetic field (attracting arrows A) in theanterior region of the oral cavity. The attracting magnetic field Aresists posterior movement of the tongue and/or soft palate/uvula, whichis a desired therapeutic objective.

The posterior magnetic regions 18 a of the structure 14 (located onopposite sides of the tongue in the back of the oral cavity) have aN-pole orientation toward the oral cavity. The magnetic region 18 athereby presents N-poles oriented in a generally facing relationshipwith the N-poles of the magnet regions 16 a, 16 b, and 16 c, which arelocated in the posterior of the tongue and/or soft palate/uvula. The N-Norientation between the posterior magnetic regions 18 a of the structure14 and the posterior magnetic regions 16 a, 16 b, and 16 c of thestructure 12 generates a repelling magnetic field (repelling arrows R)in the posterior region of the oral cavity. The fluxes of the arraysinteract to create an anterior directed force, which is relativelystable where the implant is well-aligned in a medial-lateral direction.

In this arrangement, the middle magnet regions 18 b of the structure 14(between the posterior and anterior magnetic regions 18 a and 18 c onopposite sides of the tongue along the lateral sides of the oral cavity)have a N-pole orientation toward the anterior magnetic region 18 c.Juxtaposed between the attracting magnetic field in the anterior regionof the oral cavity and the repelling magnetic field in the posteriorregion of the oral cavity, the N-pole orientation of the middle magneticregion 18 b's direct flux in the magnetic field between the anteriormagnetic region 18 c's (which attracts the tongue and/or softpalate/uvula at the anterior region of the oral cavity) and theposterior magnetic region 18 a's (which repels the tongue and/or softpalate/uvula at the posterior region of the oral cavity), withoutimposing a significant destabilizing side-to-side attracting force onthe tongue and/or soft palate. The magnetic regions 18 a, 18 b, and 18 chave been sized and configured to create a relatively constant magneticflux or a relatively constant magnetic flux gradient in the workingrange where the implant 12 is expected to be positioned.

The magnetic regions 18 a, 18 b, and 18 c shown in FIGS. 16A and 16B canbe variously constructed. For example, FIGS. 17A and 17B areillustrative examples of magnetic arrays comprising seven separatepermanent magnets 18(1) to 18(7), whose N-polarities have been labeled.FIG. 17A is directed to a chin-mounted or mouth piece structure, likeFIG. 16A. FIG. 17B is directed to a neck-collar structure, like that inFIG. 16B.

Magnets 18(1) and 18(7) each comprise a posterior magnetic region 18 a.Magnets 18(3), 18(4), and 18(5) collectively comprise the anteriormagnetic region 18 c. Magnets 18(2) and 18(6) each comprise a middlemagnetic region 18 b. As shown in FIGS. 17A and 17B, the magnetic fieldscan be manipulated by changing direction of the magnets themselves.

FIG. 15 illustrates (Curve MM) the force versus distance relationshipbetween arrays 12 and 14 as shown in FIG. 16A/B and FIG. 17A/B, as justdescribed. The slope of Curve MM in FIG. 15 demonstrates how magnitudeof a magnetic force field (y-axis) between the two arrays 12 and 14 (asshown in FIGS. 16A/B or 17A/B) does not decrease significantly withinthe boundaries of the working range (x-axis). Curve MM furtherdemonstrates that the slope diminishes substantially within theboundaries of the working range.

FIG. 18A is a diagrammatic representation of a finite element analysisshowing the flux direction lines for the magnetic arrays of a type shownin FIGS. 16A/B and 17A/B. FIG. 18B is another diagrammaticrepresentation of a finite element analysis showing distribution of themagnetic field force for these magnetic arrays 16 a/16 b/16 c and 18(1)to 18(7). As seen in FIG. 18B, the arrays generate a titrated magneticfield F1/F2/F3 having a force that generates a relatively constant forceF3 over a working range of 3 cm to 4 cm. This relatively constantmagnetic field force F3 allows the structure 12 implanted in the tongue,soft palate, or uvula to vary in its position within the working rangedue to normal functions without significant loss of attracting magneticforce with respect to the structure 14.

D. Tethered Magnetic Structures

FIGS. 39A and 39C show representative embodiments of a tetheredferromagnetic structure 120 implanted in an anterior region of a tonguein proximity to a magnetic structure 14 as previously described, e.g., amouthpiece carried within the oral cavity or an external carrier placedon or under the chin or about the neck. For purposes of illustration,FIG. 39A shows the magnetic structure 14 worn externally under the chin,while in FIG. 39C the magnetic structure 14 is part of a chin cup. Asseen in FIGS. 39A and 39C, the ferromagnetic structure 120 includes oneor more permanent magnets or ferromagnetic materials implanted in tissuebeneath the tongue or in an anterior region of the tongue, respectively.In use, the ferromagnetic structure 120 in the tongue magneticallyinteracts with the magnetic structure 14. The ferromagnetic structure120 and the magnetic structure 14 are arranged in an attractingorientation, to draw the tongue forward and/or resist posterior movementof the tongue in a manner that would otherwise occlude the airway.

Due to the relatively close proximity of the ferromagnetic structure 120to the magnetic structure 14, the magnitude of the magnetic force fieldis maximized. Further, to resist migration of the ferromagneticstructure 120 within tissue in the presence of the relatively strongmagnetic force field, the ferromagnetic structure 120 further includesan anchoring system 122. The anchoring system 122 comprises anon-magnetic holding or anchoring structure 124 that is tethered by aband, suture, or another means for attachment 126 to the ferromagneticstructure 120. The presence of the anchoring system 122 resistsmigration of the ferromagnetic structure 120 within tissue as a resultof the magnetic interaction with the magnetic structure 14. Furthermore,the anchoring system pulls the posterior tongue tissue in an anteriordirection to prevent collapse of the tongue. The anchoring system 122may also serve to stabilize the ferromagnetic structure 120 in arelatively large, soft tissue mass, such as the tongue.

As shown in FIGS. 39A and 39C, the anchoring structure 124 is implantedin a tissue mass spaced from and posterior to the ferromagneticstructure 120, e.g., at the back of the tongue. The anchoring structure124 can comprise, e.g., a biocompatible woven, formed, or moldedstructure made from a polymer or fiber or fabric or non-ferrous metallicmaterial, which resists deterioration, while exhibiting sufficientflexibility to prevent discomfort or affecting speech or swallowing. Asshown in FIGS. 39A and 39C, the holding structure 124 may includeperforations 128. The perforations 128 impart greater flexibility to theholding structure 124. The perforations 128 also accommodate tissuein-growth, further securing implantation in tissue. Alternatively (asshown in FIG. 39E), the anchoring structure 124 can comprise anexpandable umbrella-like structure 142 that collapses for implantation(as shown in sold lines in FIG. 39E) and that expands in situ at theimplantation site (as shown in phantom lines in FIG. 39E).

The means for attachment 126 couples or tethers the ferromagneticstructure 120 to the holding or anchoring structure 124. The means forattachment 126 may comprise a generally non-elastic material, e.g., anon-resorbable suture material, other woven biocompatible lacing orfabric, or a non-woven polymer strip such as nylon or acetal or abiocompatible metallic material such as nickel titanium alloy(Nitinol™). The means for attachment 126 may comprise a biocompatiblestem with perforations to permit tissue in-growth and may also includebarbs or hooks deploying form the stem, to further stabilize thetethered ferromagnetic structure. Alternatively (as shown in FIG. 39F),the means for attachment 126 may be sized and configured to be passed orthreaded through an aperture 144 in the anchoring structure 124 andlocked into a position of tension, e.g., using a suture lock 146 orknot. This arrangement makes it possible to adjust and control tensionwithin the implant either during initial implantation or subsequent tothe initial implantation, or both.

In an alternative embodiment, the means for attachment 126 may comprisemore elastic materials, to provide compliance and increased comfort forthe patient. For instance, when swallowing, the tongue moves in aposterior direction and elasticity may prevent arousal from sleep andfurther may avoid migration of the ferromagnetic structure 120. Theanchoring structure 124 is desirably wider than the means for attachment126, thereby providing the desired resistance for the implantedferromagnetic structure 120 against being pulled through or out of theimplanted tissue region during its magnetic interaction with theclose-by magnetic structure 14.

As shown in FIGS. 39B, 39D, 39E, and 39F, the ferromagnetic structure120 may be individually tethered to two or more anchoring structures 124by respective means for attachment 126.

In this arrangement, the desired physiologic response (resistance ofairway tissue collapse) is achieved by the magnetic structure 14 (e.g.,on head gear or a mouthpiece, as previously described) creating amagnetic field that interacts with tethered ferromagnetic structure 120implanted in the caudal anterior (front) section of the tongue or belowthe tongue. The implanted ferromagnetic structure 120 has a magneticorientation opposite to the magnetic orientation of the magneticstructure 14. The magnetic force between opposite magnetic orientationscreates an attracting force. As a result of the attracting force, thetongue is drawn forward, toward the front of the oral cavity, to resistan occlusion of the airway at the base of the tongue.

The tether attached to the magnetic structure 120 serves to efficientlytransfer the motion or movement of structure 120 to the base of thetongue (the site of the obstruction). The use of the tether is designedto avoid the situation where a magnet in the tongue positioned so as tobe moved by application of an external magnet 14 is moved anteriorly,but that motion does not translate to motion of the tongue base at thepharyngeal wall.

E. Anterior Tongue/Hyoid Muscle Magnetic Structures

FIG. 40A shows a representative embodiment of a ferromagnetic structure120 implanted in an anterior or caudal anterior region of a tongue, orin one or more hyoid muscles such as the suprahyoid muscles, e.g., themylohyoid muscles, and/or geniohyoid muscles, and/or stylohyoid muscles,and/or digastric muscles, in proximity to previously-described structure14, e.g., a mouthpiece carried within the oral cavity or an externalcarrier placed on or under the chin or about the neck. For purposes ofillustration, FIG. 40A shows the structure 14 worn externally under thechin; however, the structure 14 can comprise a removable oral appliancefitted over the teeth in the oral cavity or located in the vestibule ofthe mouth. As seen in FIG. 40A, the ferromagnetic structure 120 includesone or more permanent magnets or ferromagnetic materials 16 implanted intissue beneath the tongue or in an anterior region of the tongue,respectively. In use, the ferromagnetic structure 120 in the tonguemagnetically interacts with structure 14. The ferromagnetic structure120 and structure 14 are arranged in an attracting orientation, to drawthe tongue forward and/or resist posterior movement of the tongue in amanner that would otherwise occlude the airway.

In an alternative embodiment shown in FIG. 40B, the anteriorly-placedferromagnetic structures 16 are smaller in size than theposteriorly-placed ferromagnetic structures. The posteriorly-placedferromagnetic structures 16 are larger because the ferromagneticstructure 120 needs to exert a stronger force on the posterior side thanon the anterior side, so as to keep the tongue from collapsing andclosing off the airway. Furthermore, the posterior end of ferromagneticstructure 120 also contains an aperture 121 through which the structuremay become attached or anchored to the hyoid bone. As seen in FIG. 40C,another alternative embodiment consists of a ferromagnetic structure 120which is smooth on one side, while the embedded ferromagnetic structuresproject from the opposite side.

As seen in FIGS. 40A to 40C, due to the relatively close proximity ofthe ferromagnetic structure 120 to structure 14 as well as the largearea covered by ferromagnetic structure 120, the magnitude of themagnetic force field is maximized.

In this arrangement, the desired physiologic response (resistance ofairway tissue collapse) is achieved by structure 14 (e.g., on head gearor a mouthpiece, as previously described) creating a magnetic field thatinteracts with ferromagnetic structure 120 implanted in the caudalanterior (front) section of the tongue or below the tongue. Theimplanted ferromagnetic structure 120 has a magnetic orientationopposite to the magnetic orientation of structure 14. The magnetic forcebetween opposite magnetic orientations creates an attracting force. As aresult of the attracting force, the tongue is drawn forward, toward thefront of the oral cavity, to resist an occlusion of the airway at thebase of the tongue.

IV. OTHER REPRESENTATIVE MAGNETIC STRUCTURES FOR DYNAMIC TISSUE REGIONS

A. Self-Centering Magnetic Structures

FIG. 19 shows in a diagrammatic way a magnetic system comprising twomagnetic structures 12 and 14. As described before, the structures aresized and configured to be placed in or on spaced apart tissue regionsin a mutually aligned orientation that generates magnetic interactionbetween the two structures. Depending upon the polarities of the twostructures 12 and 14, the magnetic interaction can comprise, either amagnetic attracting force between the two structures, to resist movementof the two tissue regions away from each other, or a magnetic repellingforce between the two structures, to resist movement of the two tissueregions toward each other, or a combination of these and other forces.

As stated before, unless the structures 12 and 14 are aligned in atheoretically ideal fashion, the magnetic interaction will urge the mostmobile of the structures (in FIG. 19, the structure 12) to seek analignment with the least mobile of the structures (in FIG. 19, thestructure 14) closest to the theoretically ideal position. Under thesecircumstances, the better the structures 12 and 14 are aligned, the lessmagnetic force is lost and the less torque is experienced by the mostmobile structure. Practically speaking from both an anatomic andsurgical perspective, it is difficult to achieve and maintaintheoretically ideal alignment of magnetic structures carried in or ontissue. Given this difficulty, due to misalignment, a surgicallyimplanted magnetic system may dissipate some or a large part of theintended magnetic force.

In the system shown in FIG. 20A, at least one of the structures 12 or 14comprises a self-centering magnetic structure 130. The self-centeringmagnetic structure 130 comprises at least one mobile magnet 132 enclosedin a capsule or container 134. The shape of the mobile magnet 132relative to the capsule or container 134 is configured and sized topermit the mobile magnet 132 to translate or move freely within theboundaries of the capsule or container 134 in response to misalignedmagnetic interaction with the other structure 14. For example, as shownin FIG. 20A, when misalignment between the self-centering structure 130and the other structure 14 occurs, the mobile magnet 132 in theself-centering structure 130 will translate or move within theboundaries of the capsule or container 134 (as shown in FIG. 20B) toseek a theoretically ideal alignment with respect to the other structure14. As relative tissue orientations dynamically change, the mobilemagnet 132 will also dynamically translate or move within the boundariesof the capsule or structure 134 to maintain the best possible alignmentwith the other structure. The boundaries of the capsule or container 134provide a region of open space 136 where the mobile magnet can maneuverrelatively unimpeded to seek the best possible alignment with the otherstructure. In FIGS. 20A and 20B, a Tongue System 10 a is shown forpurposes of illustration. As shown in FIGS. 20A and 20B, the TongueSystem 10 a comprises a self-centering magnetic tongue implant 130interacting with an internal magnetic array 14.

As shown in FIG. 21A, the self-centering magnetic structure 130 maycomprise a magnetic structure 14 like that previously described that issized and configured to be placed in or on tissue outside an airway,e.g., comprising a carrier worn on the chin or about the neck. In thisarrangement, the self-centering magnetic structure is intended to beplaced in association with another magnetic structure 12 sized andconfigured to be placed in or on tissue within an airway, e.g., on thetongue, soft palate/uvula, or both. Together, the self-centeringstructure and the other structure 12 form a system 10 a, 10 b, or 10 c,as previously described. In FIG. 21A, a Tongue System 10 a is shown forpurposes of illustration. As shown in FIG. 21A, the Tongue System 10 acomprises a tongue implant 12 interacting with an external,self-centering magnetic structure 130.

As shown in FIG. 21B, the self-centering magnetic structure 130 cancomprise a carrier 26 that includes at least one capsule 134 housing atleast one mobile magnet 132. In the embodiment shown in FIG. 21B, thecapsule 134 is compartmentalized for purposes of illustration into twospatially separate zones Z1 and Z2, each housing at least one mobilemagnet 132 (generally corresponding to the posterior and intermediateregions 18 a and 18 b shown in FIG. 12C). In the arrangement, the mostanterior magnetic region (region 18 c in FIG. 12C) can comprise one ormore magnets that are not mobile, or vice versa. In the embodiment shownin FIG. 21C, the capsule 134 is compartmentalized for purposes ofillustration into three separate zones Z1, Z2, and Z3 (generally similarto the regions 18 a, 18 b, and 18 c in FIG. 12C), each housing at leastone mobile magnet 132. The zones Z1, Z2, and Z3 can also be viewed asbeing separate capsules 134. As shown in FIGS. 2B and 21C, each zone orcapsule may contain a plurality of smaller mobile magnets, commensuratewith the available volume of the zone or capsule, allowing the mobilemagnets to move freely and align themselves within the capsule with theother structure 12. The separate zones Z1, Z2, and Z3 or capsules 134keep the mobile magnets 132 in spatial zones, so that the mobile magnets132 do not congregate in one location. Each zone Z1, Z2, and Z3 orcapsule 134 is sized and configured to accommodate allowable, definedand controlled movement of the mobile magnet or magnets 132 housedwithin its boundaries. Alternatively, as shown in FIG. 21D, any or allzones Z1, Z2, or Z3 or capsules 134 may contain a single, larger mobilemagnet 132.

As shown in FIGS. 21E and 21F, the self-centering magnetic structure 130can include a single zone or capsule that is centrally located, to be,in use, essentially under the tongue. The zone or capsule 134 canaccommodate a single, larger mobile magnet 132 (as shown in FIG. 21E) ormore than one smaller mobile magnet 132 in the centrally-located zone orcapsule 134 that is essentially located under the tongue (as shown inFIG. 21F).

Because the self-centering magnetic structures 130 shown in FIGS. 21A to21F are intended to be placed on external tissue, the internal volume ofthe zones or capsules can be relatively large (compared to a capsule ina structure that is intended to be implanted in tissue), therebyproviding a relatively large freedom of movement for the mobile magnetit houses.

Alternatively, as shown in FIG. 22A, the self-centering magneticstructure 130 can be sized and configured for placement within an oralcavity, e.g., inside, outside, or on top of the lower or upper teeth, ashas already been described. In this arrangement, the self-centeringmagnetic structure 130 is intended to be placed in association withanother magnetic structure (in FIG. 22A, magnetic structure 12) sizedand configured to be placed in or on tissue within an airway, e.g., onthe tongue, soft palate/uvula, or both. Together, the self-centeringstructure and the other structure 12 form a system 10 a, 10 b, or 10 c,as previously described. In FIG. 22A, a Soft Palate System 10 b is shownfor purposes of illustration. The Soft Palate System 10 b in FIG. 22Acomprises a soft palate implant 12 interacting with an internal,self-centering magnetic structure 130.

In this embodiment, like the embodiments shown in FIGS. 21A to 21F, theself-centering magnetic structure 130 comprises at least one capsule 134housing at least one mobile magnet 132. In FIG. 22B, like FIG. 21B, thecapsule 134 is compartmentalized for purposes of illustration into oneor more separate spatial zones Z1 and Z2 each sized and configured toaccommodate unimpeded movement of at least one mobile magnet 132 withinits boundaries. As before stated, the zones Z1 and Z2 can also be viewedas being separate capsules 134. The separate zones Z1 and Z2 or capsules134 keep the mobile magnets 132 in spatial zones, so that the mobilemagnets 132 do not congregate in one location. Because the structureshown in FIG. 22B is intended to be placed within the airway, theinternal volume of the zones Z1 and Z2 or capsules 134 will berelatively smaller, compared to a capsule in a structure like that inFIG. 21B, which is intended to be externally worn. Still, the zones Z1and Z2 or capsules 134 and mobile magnets 132 they house can be mutuallysized and configured to provide a relatively large freedom of movementfor the mobile magnets 132. As shown in FIG. 22B, each zone Z1 and Z2 orcapsule 134 may contain a single mobile magnet, or alternatively, asshown in FIG. 22C, each zone or capsule 134 may be compartmentalized tocontain a plurality of smaller mobile magnets 132. The number of zonesand/or mobile magnets can vary, as shown in FIGS. 21A to 21F. Also, aspreviously described, a given structure 14 can include both mobilemagnets 132 and non-mobile magnets 18 (for example 18 c shown in FIG.21B). Many variations are contemplated.

As shown in FIG. 23A, the self-centering magnetic structure 130 maycomprise a magnetic structure 12, like that previously described, thatis sized and configured to be placed in or on tissue inside an airway,e.g., comprising a carrier placed in or on a tongue and/or a softpalate/uvula, as has already been described. In this arrangement, theself-centering magnetic structure 130 is intended to be placed inassociation with another magnetic structure 14 sized and configured tobe placed in or on tissue outside an airway (on the chin or neck) orinside the airway (on the lower teeth). Together, the self-centeringstructure and the other structure 12 form a system 10 a, 10 b, or 10 c,as previously described. In FIG. 23A, a Tongue System 10 a is shown forpurposes of illustration. The Tongue System 10 a in FIG. 23A comprises aself-centering tongue implant structure 130 interacting with an externalmagnetic structure 14. In this arrangement, the interaction between theself-centering tongue implant structure 130 and the external structureplaces a torque on the tongue. It should be appreciated that otherstructures 14 can also comprise a self-centering external structure of atype shown in FIGS. 21A/B/C/D/E/F or a self-centering internal structureof a type shown in FIGS. 22A/B/C.

In this embodiment, like the previous embodiments shown in FIGS.21A/B/C/D/E/F and 22 A/B/C, the self-centering magnetic structure 130comprises at least one capsule 134 housing at least one mobile magnet132. In FIG. 23B, like FIGS. 21B and 22B, the capsule 134 iscompartmentalized into separate spatial zones Z(N) sized and configuredto accommodate unimpeded movement of at least one mobile magnet 132within its boundaries. In FIG. 23B, there are eight zones shown (i.e.,N=8). These zones Z(N) can also be viewed as separate capsules 134. Asbefore described, the separate zones Z(N) or capsules 134 keep themobile magnets 132 in spatial zones, so that the mobile magnets 132 donot congregate in one location. Because the structure 130 shown in FIG.23B is intended to be placed within a tongue or soft palate, theinternal volume of the zones Z(N) or capsules 134 will be relativelysmaller, compared to a capsule in a structure like that in FIG. 21B,which intended to be externally worn. Still, the zones Z(N) or capsules134 and mobile magnets 132 they house can be mutually sized andconfigured to provide a relatively large freedom of movement for themobile magnets 132. As shown in FIG. 23B, any or all zones Z(N) orcapsules 134 may contain a single mobile magnet 132, or alternatively,as shown in FIG. 23C, any or all zones Z(N) or capsule 134 may becompartmentalized to contain a plurality of smaller mobile magnets 132.The number of zones and/or mobile magnets can vary, as shown in FIGS.21A to 21F. Also, as previously described, a given structure 14 caninclude both mobile magnets 132 and non-mobile magnets 18 (like thatshown in FIG. 21B). Many variations are contemplated.

As shown in FIGS. 24A/24B/24C the mobile magnet 132 housed within agiven capsule 134 or zone can comprise various shapes. For example, themobile magnet 132 may have either a disk-like or spherical configuration(FIG. 24A), or a cylindrical configuration (FIG. 24B), or a triangularconfiguration (FIG. 24C). The shape can be selected to affect the mannerin which the mobile magnet 132 moves or translates within the capsule.For example, the mobile cylindrical magnet 132 (FIG. 24B) can rolleasily within the capsule 134 in order to align in a proper position.The mobile triangular magnet 132 (FIG. 24C) can include a base having astronger magnetic flux than the apex of the triangle, to help directflux in a desired direction.

B. Off-Center Magnetic Structures

The tissue on the lateral sides of the tongue, due to its decreasedthickness, may be easier to move than the tissue along the midline ofthe tongue. Thus, a magnetic structure that is placed in or on tissue ononly one side of the tongue can effectively repel a correspondinglypositioned magnetic implant in or on a pharyngeal wall.

FIG. 25 shows a cross-section of a collapsed pharyngeal conduit, likeFIG. 3 but shown from another perspective, sufficient to cause an apneicepisode. FIG. 25 also shows the tongue with an implanted magneticstructure 70. Magnetic tongue structure 70 comprises at least twomagnets 16 oriented in the same direction, substantially perpendicularto the midline of the tongue. As can be seen in FIG. 25, the location ofmagnetic tongue structure 70 is generally perpendicular and off-centerwith respect to the raphé of the tongue. That is, as the embodiment inFIG. 25 shows, all of the structure 70 occupies one side of the tonguealong the raphé. Essentially no part of the structure 70 (and thereforeno magnets) extends across the raphé to the opposite side of the tongue.

FIG. 26A shows a new position of the tongue (compared to FIG. 25) due tothe interactions between the off-center magnetic tongue structure 70 andan external magnetic structure 14 of the type shown in FIG. 12C/E, whichtogether form an embodiment of a Tongue System 10 a. Forces of magneticattraction between the off-center structure 70 and the structure 14 inFIG. 26A pull the off-center structure 70 anteriorly toward thepharyngeal wall, opening one side of the pharyngeal airway, sufficientto prevent the apneic episode.

FIG. 26B shows a new position of the tongue (compared to FIG. 25) due tothe interactions between the off-center magnetic tongue structure 70 andan external magnetic structure 14 of the type shown in FIG. 12F, whichform another embodiment of a Tongue System 10 a. Forces of magneticattraction between the off-center structure 70 and the structure 14 inFIG. 26B pull the off-center magnetic structure 70 toward the oppositeside of the tongue with respect to the location of the off-centermagnetic structure 70, opening one side of the pharyngeal airway,sufficient to prevent the apneic episode.

FIG. 27 shows a new position of the tongue (compared to FIG. 25) due tothe interactions between the off-center magnetic tongue structure 70 andan internal magnetic structure 14′ placed in or on the posteriorpharyngeal wall across from the region of the tongue where theoff-center magnetic structure 70 is implanted. The internal magneticstructure 14′ carries one or more magnets 18 having a polarity facingthe airway that is the same as the off-center magnetic structure 70. Theoff-center magnetic structure 70 magnetically interacts with thepharyngeal wall structure 14 by repelling. Forces of magnetic repulsionbetween the off-center structure 70 and the structure 14 in FIG. 27 pushthe magnetic tongue structure 70 anteriorly toward the mouth, openingone side of the pharyngeal airway, sufficient to prevent the apneicepisode.

C. Rudder-Type Magnetic Structures

FIG. 28 shows a cross-section of a collapsed pharyngeal conduit, likeFIG. 3 but shown from another perspective, sufficient to cause an apneicepisode. FIG. 28 also shows the tongue with an implanted, rudder-typemagnetic structure 72. The magnetic structure 72 comprises a firstregion or arm 74 carrying at least two magnets 16 oriented in the samedirection transversally along the midline of the tongue. As can be seenin FIG. 28, the location of the magnets 18 in the arm 74 is off-centerwith respect and generally perpendicular to the raphé of the tongue, aspreviously described with respect to FIG. 25. However, unlike theembodiment shown in FIG. 25, the magnetic structure 72 includes a secondregion or arm 76 that extends across the raphé to the opposite side ofthe tongue. The region or arm 76 is free or essentially free of magnets,so that essentially no magnets occupy this region of the tongue.

The magnet-free region or arm 76, which extends to a location of thetongue not occupied by the magnets 16, acts as a rudder. Rudder-typemagnetic structures 72 of the type shown in FIG. 28 are variants of theoff-center magnetic structures 70 shown in FIG. 25. The presence of therudder 76 serves to move more soft tissue than the off-center structure70 shown in FIG. 25 and/or to further stabilize the structure 72 duringuse.

FIG. 29A shows a new position of the tongue (compared to FIG. 28) due tothe interactions between the rudder-type magnetic structure 72 and anexternal magnetic structure 14 of the type shown in FIGS. 12C and 12E,which together form an embodiment of a Tongue System 10 a. Forces ofmagnetic attraction between the rudder-type structure 72 and thestructure 14 in FIG. 29A pull the magnetic portion of the tonguestructure 72 anteriorly toward the mouth. This is because the magnets 16of the structure 72 have an S-polarity facing toward the front(anterior) of the oral cavity, and the magnets 18 of the structure 14have an opposite N-polarity facing inward toward the oral cavity, orvice versa. The rudder portion 76, being essentially free of magnets, isnot magnetically attracted, but remains implanted in tissue across theraphé on the other side of the tongue. As a result, the structure 72will pivot about the rudder portion 76 toward the external magneticstructure 14. The additional surface area of the rudder portion 76 willdraw more tissue in the direction of the pivot, and will also serve as atissue anchor that lends overall stability to the structure 72. Themagnetic interaction opens one side of the pharyngeal airway, sufficientto prevent the apneic episode.

FIG. 29B shows a new position of the tongue (compared to FIG. 25) due tothe interactions between the rudder-type magnetic structure 72 and anexternal magnetic structure 14 of the type shown in FIG. 12F, which formanother embodiment of a Tongue System 10 a. Forces of magneticattraction between the rudder-type structure 72 and the structure 14 inFIG. 29B pull the magnetic portion 76 of the rudder-type magneticportion of the tongue structure 72 toward the opposite side of thetongue with respect to the location of the magnetic portion of thestructure 72. This is because the magnets 16 of the structure 72 have anS-polarity facing toward the front (anterior) of the oral cavity, andthe magnets 18 of the structure 14 have an opposite N-polarity facinginward toward the oral cavity, or vice versa. The rudder portion 76,being essentially free of magnets, is not magnetically attracted, butremains implanted in tissue across the raphé on the other side of thetongue. As a result, the structure 72 will pivot about the rudderportion toward the external magnetic structure 14. The additionalsurface area of the rudder portion 76 will draw more tissue in thedirection of the pivot, and will also serve as a tissue anchor thatlends overall stability to the structure 72. The magnetic interactionopens one side of the pharyngeal airway, sufficient to prevent theapneic episode.

FIG. 30 shows a new position of the tongue (compared to FIG. 28) due tothe interactions between the rudder-type magnetic structure 72 and aninternal magnetic structure 14 placed in or on the posterior pharyngealwall across from the region of the tongue where the rudder-type magneticstructure 72 is implanted. The internal magnetic structure 14 carriesone or more magnets 18 having a polarity facing the airway that is thesame as the rudder-type magnetic structure 72. The rudder-type magneticstructure 72 magnetically interacts with the pharyngeal wall structure14 by repelling. Forces of magnetic repulsion between the rudder-typestructure 72 and the structure 14 in FIG. 30 push the magnetic portion74 of the tongue structure 72 anteriorly toward the mouth. This isbecause the magnets 16 of the structure 72 have an N-polarity facing theairway, and the magnets 18 of the structure 14 have the same N-polarityfacing the airway, or vice versa. The rudder portion 76, beingessentially free of magnets, is not magnetically attracted, but remainsimplanted in tissue across the raphé on the other side of the tongue. Asa result, the structure 72 will pivot about the rudder portion 76 awayfrom the internal magnetic structure 14. The additional surface area ofthe rudder portion 76 will push more tissue in the direction of thepivot, and will also serve as a tissue anchor that lends overallstability to the structure 72. The magnetic interaction opens one sideof the pharyngeal airway, sufficient to prevent the apneic episode.

The rudder portion of a rudder-type magnetic structure 72 can bevariously sized and configured. For example, as shown in FIGS. 31A/B/C,the main body 78 of the structure 72 can include a rudder portion 76having a surface area that is increased by providing an appendage 92(see FIGS. 31A and 31B) that projects outward at a desired angle (e.g.,45° to 90°) from the rudder portion 76. That is (see FIGS. 31A and 31B),given that the main body 78 of the structure lies along a longitudinalaxis 84, the axis 82 of the appendage 92 lies at an angle from thelongitudinal axis 84. The appendage 92 gives greater depth to theoverall implant in the direction of the magnetic field. Generally,magnetic implants having greater depth apply more force to tissue,because of increased surface area and mass. Thus, the appendage 92serves to apply more force and stability to the implant. Additionally,the appendage 92 may also carry embedded sources of magnetism, in whichcase the appendage would also lower the distance between magneticstructure 12 and an external magnetic structure 14 with which itmagnetically interacts.

As FIGS. 31C and 31D show, the location of magnetic implant 72, whenimplanted, is desirably centered with respect to the raphe, with thelongitudinal axis 84 of the main body extending transversely of theraphé and the axis 82 of the rudder appendage 92 extending generallyparallel to the raphé. As FIG. 31C shows, the implant 72 is divided intotwo parts by the raphé of the tongue. On one side 88 of the raphe, atleast two magnets 16 are carried by the structure 70. On the other side86 of the raphé lies the rudder portion 76 with appendage 92, which isdesirably free or essentially free of magnetic material. As FIG. 31Dshows, the portion 76 and its appendage 92 act as a rudder to help movemore tongue tissue as a result of magnetic attraction and/or repulsionbetween the magnet-carrying side 88 of the implant and another magneticstructure of a type previously described.

FIGS. 32A and 32B show an alternative embodiment of a rudder-typemagnetic structure 98 sized and configured for placement in a tongue. Inthe embodiment, the rudder-type magnetic structure 98 comprises a mainbody 100 having a longitudinal axis 104. The main body 100 comprises afirst region 106 carrying a first array of one or more magnets 16(1) anda second region 108 carrying a second array of one or more magnets16(2). As FIGS. 32A and 32B show, the polarity of the magnets in thefirst array 16(1) is generally opposite to the polarity of the secondarray 16(2). The main body 100 further comprises an intermediate rudderappendage 112 between the first and second regions 106 and 108 having anaxis 102 that projects at an angle from the longitudinal axis 104. Therudder appendage 112 is desirably free or essentially free of magnets.In the illustrated embodiment (see FIGS. 32A and 32B), the magnets ofthe first array 16(1) have a N-polarity facing in the direction of therudder appendage 112, and the magnets of the second array 16(2) have aS-polarity facing the direction of the rudder appendage 112.

FIG. 33 shows a cross-section of a collapsed pharyngeal conduit, likeFIG. 3 but shown from another perspective, sufficient to cause an apneicepisode. FIG. 33 also shows the rudder-type structure 98 shown in FIGS.32A/B implanted in the tongue. As can be seen in FIG. 33, the main body100 is implanted with its longitudinal axis 104 extending generallytransversely of the raphé of the tongue, with the first region 106located on one side of the raphé and the second region 108 located onthe opposite side of the raphé. The rudder appendage 112 occupies theraphé between the first and second regions, and the axis 102 of therudder appendage 112 extends generally parallel to the raphé.

FIG. 34A shows a new position of the tongue (compared to FIG. 33) due tothe interactions between the rudder-type structure 98 shown in FIGS.32A/B and an external magnetic structure 14 of the type shown in FIGS.12C/E, which together form an embodiment of a Tongue System 10 a. Thestructure 14 carries magnets 18 having a polarity facing the oral cavitythat are opposite to the polarities of the magnets of the second array16(2) and the same as the polarities of the magnets of the first array16(1). In the illustrated embodiment, the magnets 18 have a N-polarityfacing the oral cavity. As a result, forces of magnetic attraction aregenerated between the structure 14 and the second array 16(2), whereasforces of magnetic repulsion are generated between the structure 14 andthe first array 16(1). The attracting forces pull the second portion 108of the structure 98 anteriorly toward the mouth, whereas the repellingforces push the first portion 106 of the structure 98 posteriorly towardthe pharyngeal wall. The rudder appendage 112, being essentially free ofmagnets, is not magnetically attracted or repelled, but remainsimplanted in tissue in the region of the raphé between the two oppositesides of the tongue. The rudder stabilizes the push and pull of thedifferent magnetic interactions. The magnetic interactions open one sideof the pharyngeal airway, sufficient to prevent the apneic episode.

FIG. 34B shows a new position of the tongue (compared to FIG. 33) due tothe interactions between the rudder-type structure shown in FIGS. 32A/Band an external magnetic structure 14 of the type shown in FIG. 12E,which form another embodiment of a Tongue System. The structure 14carries magnets 18 on only the side of the tongue occupied by the firstarray 16(1). The magnets 18 have a polarity facing the oral cavity thatis the same as the polarities of the magnets of the first array 16(1)and opposite to the polarities of the magnets of the second array 16(2).The attracting forces pull the second portion 108 of the structure 98toward the opposite side of the tongue, whereas the repelling forcespush the first portion 106 of the structure posteriorly toward thepharyngeal wall. The rudder appendage 112, being essentially free ofmagnets, is not magnetically attracted or repelled, but remainsimplanted in tissue in the region of the raphé between the two oppositesides of the tongue. As a result, the second portion 108 of thestructure 98 will pivot toward the external magnetic structure 14, asthe first portion 106 of the structure 98 pivots away from the externalmagnetic structure 14. The rudder appendage 112 stabilizes thepush-and-pull of the different magnetic interactions, and will draw moretissue in the direction of the pivot. The magnetic interactions open oneside of the pharyngeal airway, sufficient to prevent the apneic episode.

FIG. 35 shows a new position of the tongue (compared to FIG. 33) due tothe interactions between the rudder-type structure shown in FIGS. 32A/Band an internal magnetic structure 14 placed in or on the posteriorpharyngeal wall across from the region of the tongue where the firstarray of the structure is implanted. The internal magnetic structure 14carries one or more magnets 18 having a polarity facing the airway thatis the same as the magnets in the second array 16(2) and that isopposite to the magnets in the first array 16(1). As a result, forces ofmagnetic repulsion are generated between the structure 14 and the secondarray 16(2), whereas forces of magnetic attraction are generated betweenthe structure 14 and the first array 16(1). The repelling forces pushthe second portion 108 of the structure 98 toward the oral cavity,whereas the attracting forces pull the first portion 106 of thestructure posteriorly toward the pharyngeal wall. The rudder appendage112, being essentially free of magnets, is not magnetically attracted orrepelled, but remains implanted in tissue in the region of the raphébetween the two opposite sides of the tongue. As a result, the secondportion 108 of the structure 98 will pivot away from the internalmagnetic structure 14, as the first portion 106 of the structure 98pivots toward the internal magnetic structure 14. The rudder appendage112 stabilizes the push-and-pull of the different magnetic interactions,and will draw tissue in the direction of the pivot. The magneticinteractions open one side of the pharyngeal airway, sufficient toprevent the apneic episode.

D. Ferromagnet With an Elastic Component

In an alternative embodiment, an implantable ferromagnetic structure 136used in the tongue, soft palate, or pharyngeal wall can compriseferromagnetic material 138 coupled to one or more elastic components140, as shown in FIGS. 41A and 41B. The elastic component coupled to theferromagnetic material 138 is sized and configured to deflect under loadin a prescribed manner and to recover an initial shape when unloaded. Asshown in FIGS. 41A and 41B the elastic component 140 comprises a spring.

The spring form of the elastic component 140 may vary. It may, e.g.,comprise a helical tension or compression spring, in which wire iswrapped in a coil that resembles a screw thread, as shown in FIG. 41A.Alternatively, the elastic component 140 may comprise a leaf spring,comprising plate elements secured. Still alternatively, the elasticcomponent 140 may comprise a spiral spring made from flat strip or wirecoiled about the ferromagnetic material 138. Still alternatively, theelastic component 140 may comprise a torsion-bar spring.

The ferromagnetic material 138 desirably comprises one or more permanentmagnets. The shape of the ferromagnetic material 138 need not becylindrical, as shown in FIG. 41A. Other sizes, shapes, andconfigurations can be used, including cubes, pyramids, tetrahedrons, andvarious polyhedrons.

As shown in FIG. 41A, the elastic component 140 may be made out of metalor a polymer, desirably a rigid polymeric material. The elasticcomponent 140 may consist of a single piece or comprise a construct ofmultiple elastic components. In spring form, the shape of the elasticcomponent 140 need not be helical (as shown in FIG. 41A), but otherconstructions capable of deflecting under load can be used. The set upof a spring-form elastic component 140 could resemble a trampoline withmultiple springs or elastic components attached peripherally about theferromagnetic material 138. The spring-form elastic component 140 canalso be tuned to any amount of force needed by modifying the pitch, thenumber of turns, the thickness and the overall angle in the spring's“cone.”

As shown in FIG. 41B, the configuration of the spring-form elasticcomponent 140 makes possible its use as an anchor, capable of attachingthe ferromagnetic material 138 into soft tissue, by twisting. Thepresence of the spring-form elastic component 140 can thus eliminate theneed to use sutures for attachment of the structure 136 to soft tissue.The spring-form elastic component 140 can also be secured (e.g., like abone screw) to a bone structure, and, in this arrangement, also serve asa tethering device for the ferromagnetic structure 138. In whateverform, the elastic component 140 may be embedded or coated in a siliconmatrix or soft material, as may be the ferromagnetic material 138. Thepresence of the elastic component on the ferromagnetic structure 136 canhelp stabilize torque in a system that incorporates ferromagneticimplants. Stabilizing the torque can bring about more predictability inthe ferromagnetic implants.

E. Alternative Embodiments to the Tongue, Soft Palate and CombinedSystems

In certain cases, the above-described Tongue, Soft Palate, and CombinedSystems may not provide enough attractive magnetic force to maintain apatent airway. Under these circumstances, the respective Systemdesirably includes at least one additional structure that interactionsto provide a magnetic force that complements the attractive magneticforce to maintain a patent airway.

1. Complementary Tongue System

FIGS. 4E and 4F show alternative embodiments of the Tongue System thatprovide a complementary magnetic force to further resist the collapse ofthe tongue. In the representative embodiment shown in FIGS. 4E and 4F,the magnetic structure 12 is positioned in or on the tongue, aspreviously described. More specifically, magnetic structure 12 can bepositioned either in the anterior or in the posterior region of thetongue. In FIG. 4E, the magnetic structure 14 (as previously described),which the magnetic structure 12 interacts with by attraction, ispositioned outside the airway (e.g., on the chin), whereas in FIG. 4D,the magnetic structure 14 is positioned within the airway (e.g., in theoral cavity).

Furthermore, as shown in FIGS. 4E and 4F, to provide a complementarymagnetic force for further resisting the collapse of the tongue, theTongue System includes a magnetic structure 15 positioned in or on theposterior pharyngeal wall, generally opposite of magnetic structure 12in or on the tongue. The magnetic structure 15 carries at least onemagnetic material 19 that, by magnetic interactions with the structure12, generates a magnetic force that includes at least one vector orcomponent that magnetically repels the structure 12 in or on the mobiletissue of the tongue away from the structure 15 in or on the relativelyless mobile tissue of the pharyngeal wall. In the illustratedembodiment, the magnetic material 19 of the structure 15 has a polaritythe same as the polarity of the magnetic structure 12 that it facesacross the airway. The magnetic structure 15 thereby interacts with themagnetic structure 12 across the airway by repulsion. The repellingmagnetic interaction between the magnetic structure 15 and the magneticstructure 12 in the posterior airway serves to stabilize the tongue andresist collapse of the tongue against the pharyngeal wall during sleep.The repelling magnetic interaction between structures 12 and 15 in theposterior airway complements the attracting magnetic interaction betweenthe structures 12 and 14 in the anterior airway, which likewise servesto resist posterior or other movement of the tongue toward the posteriorpharyngeal wall. The complementary magnetic forces prevent, in whole orin part, the occurrence of the airway-occluding tissue condition shownin FIG. 3. The magnetic force between the first and second ferromagneticstructures 12 and 14, coupled with the magnetic force betweenferromagnetic structures 12 and 15, work together to keep the airwayopen (i.e., patent) during sleep.

2. Complementary Soft Palate System

FIGS. 5C and 5D show alternative embodiments of the Soft Palate Systemthat provide a complementary magnetic force to further resist thecollapse of the soft palate/uvula. In the representative embodimentshown in FIGS. 5C and 5D, the magnetic structure 12 is positioned in oron the soft palate/uvula, as previously described. In FIG. 5C, themagnetic structure 14 (as also previously described), which the magneticstructure 12 interacts with by attraction, is positioned outside theairway (e.g., on the chin), whereas in FIG. 5D, the magnetic structure14 is positioned within the airway (e.g., in the oral cavity).

Furthermore, as shown in FIGS. 5C and 5D, to provide a complementarymagnetic force for further resisting the collapse of the softpalate/uvula, the Soft Palate System includes a magnetic structure 15 ispositioned in or on the posterior pharyngeal wall, generally opposite ofmagnetic structure 12 in the soft palate/uvula. The magnetic structure15 carries at least one magnetic material 19 that, by magneticinteractions with the structure 12, generates a magnetic force thatincludes at least one vector or component that magnetically repels thestructure 12 in or on the mobile tissue of the soft palate/uvula awayfrom the structure 15 in or on the relatively less mobile tissue of thepharyngeal wall. In the illustrated embodiment, the magnetic material 19of the structure 15 has a polarity the same as the polarity of themagnetic structure 12 it faces across the airway. The magnetic structure15 thereby interacts with the magnetic structure 12 across the airway byrepulsion. The repelling magnetic interaction between the magneticstructure 15 in or on the pharyngeal wall and the magnetic structure 12in or on the soft palate/uvula serves to stabilize the soft palate/uvulaand resist collapse of the soft palate/uvula against the pharyngeal wallduring sleep. The repelling magnetic interaction between structures 12and 15 in the posterior airway complements the attracting magneticinteraction between the structures 12 and 14 in the anterior airway,which likewise serves to resist posterior or other movement of the softpalate/uvula toward the posterior pharyngeal wall. The complementarymagnetic forces prevent, in whole or in part, the occurrence of theairway-occluding tissue condition shown in FIG. 3. The magnetic forcebetween the first and second ferromagnetic structures 12 and 14, coupledwith the magnetic force between ferromagnetic structures 12 a/12 b and15 a/15 b, work together to keep the airway open (i.e., patent) duringsleep.

3. Complementary Combined System

FIGS. 6C and 6D show alternative embodiments of the Combined System thatprovide a complementary magnetic force to further resist the collapse ofthe tongue and soft palate/uvula. In the representative embodiment shownin FIGS. 6C and 6D, the magnetic structure 12 b is positioned in or onthe tongue, while magnetic structure 12 a is positioned in or on thesoft palate/uvula, as previously described. More specifically, magneticstructure 12 b can be positioned either in the anterior or in theposterior region of the tongue. In FIG. 6C, the magnetic structure 14(also as previously described), which the magnetic structure 12 a and 12b interacts with by attraction, is positioned outside the airway (e.g.,on the chin), whereas in FIG. 6D, the magnetic structure 14 ispositioned within the airway (e.g., in the oral cavity).

Furthermore, as shown in FIGS. 6C and 6D, to provide a complementarymagnetic force for further resisting the collapse of the tongue and thesoft palate/uvula, the Combined System includes a magnetic structure 15a and a magnetic structure 15 b. The magnetic structure 15 a ispositioned in or on the posterior pharyngeal wall, generally opposite ofmagnetic structure 12 a in or on the soft palate/uvula. The magneticstructure 15 b is positioned in or on the posterior pharyngeal wallgenerally opposite to the magnetic structure 12 b in or on the tongue.Each structure 15 a and 15 b carries at least one magnetic material 19that, by magnetic interactions with the associated structure,respectively 12 a and 12 b, generates a magnetic force that includes atleast one vector or component that magnetically repels the respectivestructure 12 a and 12 b in or on the mobile tissue of the softpalate/uvula or tongue away from the structure 15 in or on therelatively less mobile tissue of the pharyngeal wall. In the illustratedembodiment, the magnetic material 19 of the structure 15 has a polaritythe same as the polarity of the magnetic structure, respectively 12 aand 12 b, it faces across the airway. The magnetic structures 15 a and15 b thereby interact with the magnetic structures, respectively 12 aand 12 b across the airway by repulsion. The repelling magneticinteraction between the magnetic structure 15 a in or on the pharyngealwall and the magnetic structure 12 a in or on the soft palate/uvulaserves to stabilize the soft palate/uvula and resist collapse of thesoft palate/uvula against the pharyngeal wall during sleep. Likewise,the repelling magnetic interaction between the magnetic structure 15 bin or on the pharyngeal wall and the magnetic structure 12 b in or onthe tongue serves to stabilize the tongue and resist collapse of thetongue against the pharyngeal wall during sleep. The repelling magneticinteractions between structures 12 a/12 b and 15 a/15 b in the posteriorairway complements the attracting magnetic interaction between thestructures 12 a/12 b and 14 in the anterior airway, which likewiseserves to resist posterior or other movements of either the softpalate/uvula and/or the tongue against the posterior pharyngeal wall.The complementary magnetic forces prevent, in whole or in part, theoccurrence of the airway-occluding tissue condition shown in FIG. 3. Themagnetic force between the first and second ferromagnetic structures 12and 14, coupled with the magnetic force between ferromagnetic structures12 a/12 b and 15 a/15 b, work together to keep the airway open (i.e.,patent) during sleep.

V. FORCES REQUIRED TO MAINTAIN A PATENT AIRWAY

As FIGS. 36 and 37 show in a diagrammatic way, for a given individual,that a magnitude can be assigned to a force required to maintainseparation between tongue tissue (FIG. 36) or soft palate/uvula tissue(FIG. 37) from the posterior pharyngeal wall, to thereby resist thecollapse of an airway during an apneic episode. This force, designatedF-sep in FIGS. 36 and 37 can be obtained by physical measurement of agiven individual, or it can based upon measurements taken during acadaver study, or it can be selected empirically based upon generalanatomic considerations for a population of individuals, or acombination of these and other considerations.

For a given individual, a magnitude can also be assigned to acounterbalancing force (designated F-nat in FIGS. 36 and 37), whichrepresents the force exerted by natural muscular activity upon thetongue (FIG. 36) or the soft palate/uvula (FIG. 37), to enableswallowing, chewing, or speech during normal airway function. The forceF-nat can be also obtained by physical measurement of a givenindividual, or it can be selected empirically based upon generalanatomic considerations for a population of individuals, or acombination of these and other considerations.

As shown in FIGS. 36 and 37, the magnetic force (F-mag) that a givensystem 10 develops can be expressed as a function of F-sep and F-nat, orF-mag=f (F-sep, F-nat). The magnetic force can comprise an attractingforce (i.e., a force in essentially an anterior-posterior directionbetween the tongue or soft palate/uvula and the attracting magneticstructure worn on the chin or neck or on teeth within the oral cavity),a repelling force (i.e., a force in essentially an anterior-posteriordirection between repelling magnetic structures in the tongue andposterior pharyngeal wall), and/or a torquing force (i.e., a force ormoment of a force that tends to rotate the tongue or soft palate/uvulaabout an axis), and/or decentering force (i.e., a force in essentially alateral or side-to-side direction that tends to offset the tongue orsoft palate/uvula left or right), or a combination of two or more ofthese forces. The magnetic force F-mag maintains a separation betweenthe tongue and the posterior pharyngeal wall (FIG. 36), or between theuvula and the posterior pharyngeal wall (FIG. 37), or combinationsthereof, depending upon the desired therapeutic effect.

The function desirably incorporates the premise that F-sep≦F-nat, suchthat F-nat can overcome F-sep to preserve normal airway function. Ineffect, F-nat is the upper limit for the amount of force used which, toachieve an effective OSA therapy, which F-sep should not exceed. Thefunction also desirably incorporates the premise that F-mag≧F-sep, sothat the desired separation between the tongue and the posteriorpharyngeal wall is maintained. In the case of systems activated onlyduring the night, F-nat will necessarily be larger in magnitude becausethe only activities that need to be able to continue during sleep areswallowing and coughing, which require more force than speaking.

The function resolves F-sep and F-nat to provide an optimal therapeuticforce that, at night, resists collapse of the tongue or softpalate/uvula against the pharyngeal wall during sleep, yet does notaffect speech, swallowing or drinking during normal activities when thesystem is activated.

The function also desirably includes a tolerance factor ΔTol, whichtakes into account that F-nat can increase with time after implantation,as an individual develops tolerance to F-mag. F-nat can thereby increasewith time after implantation, as the individual trains himself orherself to exert more force during swallowing or speech in the presenceof F-mag to maintain normal airway function. The nature of the tolerancefactor ΔTol can be ascertained by physical measurement of a givenindividual, or it can be selected empirically based upon generalanatomic considerations for a population of individuals, or acombination of these and other considerations.

Further, in arriving at the absolute magnitude of F-sep for the tongue(whether relative to the pharyngeal wall, or uvula, or both), it hasbeen discovered that F-sep for the tongue can have two components. Thefirst component is the desired therapeutic force F(z) that is developedin an anterior-to-posterior direction, which prevents the tongue fromfalling back upon the posterior pharyngeal wall or uvula. The secondcomponent is an undesired decentralizing side loading force F(y) thatcan be exerted due to magnetic force discontinuities at the edges of thetongue implant. It has been observed that, as the edges of a magnetictongue implant start to misalign with the other magnetic structure (onthe chin or neck or on the teeth or in the uvula), the magnets at theedges of the tongue implant may start to twist in an attempt to orientthemselves to a more desired attracting arrangement. This can cause thetongue implant to twist or flip. The decentralizing side loading forceF(y) is an outcome of these edge discontinuities, which moves the tonguelaterally, i.e., to the side (the soft palate/uvula, being anatomicallyanchored on three of four sides, is significantly more resistant to aside loading force than the tongue, which is anchored essentially onlyon the posterior side).

A desired therapeutic force magnitude F(z) can, if the edgediscontinuities are not moderated, undesirably move the tonguelaterally. The magnitude of the edge discontinuities, i.e., themagnitude of F(y), can be titrated and controlled by the design of theother magnetic structure, e.g., by directing the magnetic fields of theposterior and middle regions of the structure at an angle relative tothe direction of the magnetic fields of the anterior region, as shown inFIGS. 16A/B. Further, by stabilizing the tongue implant in the mannerspreviously described, e.g., by the presence of a rudder as shown inFIGS. 28 to 35 or by the use of mobile magnets as shown in FIGS. 21 to23, the destabilizing effects of F(y) can be also counteracted.

An implant force scaling strategy like that shown in FIG. 38 can bebased upon an appreciation of these considerations. In FIG. 38, themagnitude of a force applied in an anterior-posterior direction upon thetongue necessary to achieve the desired therapeutic effect (i.e., F-sep)is indicated at A. As indicated before, this is the force required toseparate tongue tissue from the posterior pharyngeal wall or uvula, orboth, to thereby resist the collapse of an airway during an apneicepisode. The force F-sep (also shown in FIG. 36), can be obtained byphysical measurement or selected empirically based upon general anatomicconsiderations for a population of individuals, or a combination ofthese and other considerations.

In FIG. 38, the magnitude of the resistance (F-res) of a given tonguedecentered medially in response to an external side load is indicated atB. The specific magnitude of F-res can be obtained by physicalmeasurement of a given individual, or it can be based upon cadaverstudies, or it can be selected empirically based upon general anatomicconsiderations for a population of individuals, or a combination ofthese and other considerations. In FIG. 38, the magnitude of F-res (B)is expressed as a percentage of F-sep (A). That is, on the y-axis, F-sep(A) is expressed as 100% and F-res (B) is expressed as 60%. Theparticular relationship between F-sep and F-res can vary based uponanatomic considerations.

In FIG. 38, the magnitude of the anterior-to-posterior force F(z)generated by a given attracting magnetic structure (on the chin or neckor on the teeth or in the uvula, or combinations thereof) is indicatedby C. As FIG. 38 shows by the slope of C, this magnitude of F(z) willvary as a function of distance between the attracting magnetic structureand the tongue implant, as well as a function of the particularstructural characteristics and stabilization of the tongue implantitself.

In FIG. 38, the magnitude of the side load force F(y) generated by thegiven pharyngeal wall implant is indicated by D. The slope and magnitudeof D will vary based upon the design of the pharyngeal wall implant orthe uvula implant, particularly with respect to the moderation of edgediscontinuities, as previously described. The slope and magnitude of Dwill also depend upon the particular structural characteristics andstabilization of the tongue implant itself.

For a given magnetic force system affecting the tongue, the magnitude ofF(z) with respect to the magnitude of F(y) represents an Implant ScalingFactor (F-scale). F-scale can be expressed as a ratio of F(z) to F(y);that is F-scale=F(z)/F(y). The magnitude of F-scale for a given magneticforce system affecting the tongue indicates that the system is likely toachieve the desired therapeutic effect without decentering the tongue.

It has been discovered that, for a given magnetic force system affectingthe tongue, an F-scale 1 is desirable. For a given magnetic force systemaffecting the tongue, an F-scale≦1 indicates that decentering of thetongue will occur, which offsets the desired therapeutic effect. AnF-scale<1 indicates that the edge discontinuities of the attractingmagnetic structure (on the chin or neck or on the teeth) should bereduced or moderated and/or means for stabilizing the tongue implant arewarranted.

FIG. 38 also lends itself to an implant force scaling strategy. Theintersections of C and D with A and B define an optimal operating regionE for a magnetic force system affecting the tongue. In region E, F(z) isat or above the magnitude that achieves the desired therapeutic effectbut where F(y) is not at the magnitude at which side loading (i.e.,decentering of the tongue) will occur.

Experimentally, it has been determined that the force F-mag likelyrequired to keep an airway open on a cadaver using a magnetic forcesystem that affects the tongue is no more than 1000 g. It is believedthat magnetic tongue implant systems require a force of about 2 to about750 g to maintain a patent airway. More specifically, a force in therange of about 5 to about 600 g is believed to provide the desiredtherapeutic benefits in combination with control of edge discontinuitiesin the other magnetic structure on chin or neck or on the teeth andstabilization of the tongue implant itself.

It is also believed that F-mag for a magnetic force system that affectsthe palate should also be no more than 1000 g. More specifically, for amagnetic force system that affects the palate, it is believed that aforce F-mag of about 3 to about 800 g will provide therapeutic benefitswithout adversely affecting normal functioning of the airway.

VI. CONCLUSION

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention, which may be embodiedin other specific structure. While the preferred embodiment has beendescribed, the details may be changed without departing from theinvention, which is defined by the claims.

The above-described embodiments of this invention are merely descriptiveof its principles and are not to be limited. The scope of this inventioninstead shall be determined from the scope of the following claims,including their equivalents.

We claim:
 1. A system comprising at least one ferromagnetic structuresized and configured for placement in a tissue region, at least oneanchoring structure sized and configured for placement in a tissueregion spaced from the at least one ferromagnetic structure, and atleast one attachment assembly coupling the at least one anchoringstructure to the at least one ferromagnetic structure to stabilize theat lest one ferromagnetic structure in the tissue region, the attachmentassembly including an attachment element having a first end coupled tothe at least one ferromagnetic structure and a second end coupled to theat least one anchoring structure to hold the attachment elmenet in astate of tension between the at least one ferromagnetic structure andthe at least one anchoring structure, the second end including a memberfor adjusting the state of tension.
 2. A system according to claim 1further including at least one additional ferromagnetic structure sizedand configured for placement in a desired relationship with the at leastone ferromagnetic structure to magnetically interact with the at leastone ferromagnetic structure.
 3. A method comprising providing a systemas defined in claim 2, implanting the at least one ferromagneticstructure, at least one anchoring structure, and the at least oneattachment assembly in a tissue region, placing the at least oneadditional ferromagnetic structure in a desired relationship with the atleast one ferromagnetic structure, and stabilizing a desired tissueorientation by magnetic interactions between the at least oneferromagnetic structure and the at least one additional ferromagneticstructure.
 4. A method according to claim 3 further including adjustingthe state of tension prior to implantation.
 5. A method according toclaim 1 further including adjusting the state of tension duringimplantation.
 6. A method according to claim 1 further includingadjusting the state of tension after initial implantation.
 7. A methodfor reducing or preventing sleep disordered breathing events comprisingproviding a system as defined in claim 2.